.Net Interview Questions and Answers - An Interviewhelper.org Blog

IIS Isolation Levels

2009-01-29T23:10:00.000-08:00

Question :IIS Isolation Levels?
Answer :Internet Information Server introduced the notion "Isolation Level", which is also present in IIS4 under a different name. IIS5 supports three isolation levels, that you can set from the Home Directory tab of the site's Properties dialog: • Low (IIS Process): ASP pages run in INetInfo.Exe, the main IIS process, therefore they are executed in-process. This is the fastest setting, and is the default under IIS4. The problem is that if ASP crashes, IIS crashes as well and must be restarted (IIS5 has a reliable restart feature that automatically restarts a server when a fatal error occurs). • Medium (Pooled): In this case ASP runs in a different process, which makes this setting more reliable: if ASP crashes IIS won't. All the ASP applications at the Medium isolation level share the same process, so you can have a web site running with just two processes (IIS and ASP process). IIS5 is the first Internet Information Server version that supports this setting, which is also the default setting when you create an IIS5 application. Note that an ASP application that runs at this level is run under COM+, so it's hosted in DLLHOST.EXE (and you can see this executable in the Task Manager). • High (Isolated): Each ASP application runs out-process in its own process space, therefore if an ASP application crashes, neither IIS nor any other ASP application will be affected. The downside is that you consume more memory and resources if the server hosts many ASP applications. Both IIS4 and IIS5 supports this setting: under IIS4 this process runs inside MTS.EXE, while under IIS5 it runs inside DLLHOST.EXE. When selecting an isolation level for your ASP application, keep in mind that out-process settings - that is, Medium and High - are less efficient than in-process (Low). However, out-process communication has been vastly improved under IIS5, and in fact IIS5's Medium isolation level often deliver better results than IIS4's Low isolation. In practice, you shouldn't set the Low isolation level for an IIS5 application unless you really need to serve hundreds pages per second.

Advantages in IIS 6.0

2009-01-29T23:09:00.000-08:00

Question :Advantages in IIS 6.0?
Answer :http://www.microsoft.com/windowsserver2003/iis/evaluation/features/default.mspx http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/windowsserver2003/proddocs/datacenter/gs_whatschanged.asp

What are the different IIS authentication modes in IIS 5.0 and Explain Difference between basic and digest authentication modes

2009-01-29T23:06:00.000-08:00

Question :What are the different IIS authentication modes in IIS 5.0 and Explain? Difference between basic and digest authentication modes?
Answer :IIS provides a variety of authentication schemes: • Anonymous (enabled by default) • Basic • Digest • Integrated Windows authentication (enabled by default) • Client Certificate Mapping Anonymous Anonymous authentication gives users access to the public areas of your Web site without prompting them for a user name or password. Although listed as an authentication scheme, it is not technically performing any client authentication because the client is not required to supply any credentials. Instead, IIS provides stored credentials to Windows using a special user account, IUSR_machinename. By default, IIS controls the password for this account. Whether or not IIS controls the password affects the permissions the anonymous user has. When IIS controls the password, a sub authentication DLL (iissuba.dll) authenticates the user using a network logon. The function of this DLL is to validate the password supplied by IIS and to inform Windows that the password is valid, thereby authenticating the client. However, it does not actually provide a password to Windows. When IIS does not control the password, IIS calls the LogonUser() API in Windows and provides the account name, password and domain name to log on the user using a local logon. After the logon, IIS caches the security token and impersonates the account. A local logon makes it possible for the anonymous user to access network resources, whereas a network logon does not. Basic Authentication IIS Basic authentication as an implementation of the basic authentication scheme found in section 11 of the HTTP 1.0 specification. As the specification makes clear, this method is, in and of itself, non-secure. The reason is that Basic authentication assumes a trusted connection between client and server. Thus, the username and password are transmitted in clear text. More specifically, they are transmitted using Base64 encoding, which is trivially easy to decode. This makes Basic authentication the wrong choice to use over a public network on its own. Basic Authentication is a long-standing standard supported by nearly all browsers. It also imposes no special requirements on the server side -- users can authenticate against any NT domain, or even against accounts on the local machine. With SSL to shelter the security credentials while they are in transmission, you have an authentication solution that is both highly secure and quite flexible. Digest Authentication The Digest authentication option was added in Windows 2000 and IIS 5.0. Like Basic authentication, this is an implementation of a technique suggested by Web standards, namely RFC 2069 (superceded by RFC 2617). Digest authentication also uses a challenge/response model, but it is much more secure than Basic authentication (when used without SSL). It achieves this greater security not by encrypting the secret (the password) before sending it, but rather by following a different design pattern -- one that does not require the client to transmit the password over the wire at all. Instead of sending the password itself, the client transmits a one-way message digest (a checksum) of the user's password, using (by default) the MD5 algorithm. The server then fetches the password for that user from a Windows 2000 Domain Controller, reruns the checksum algorithm on it, and compares the two digests. If they match, the server knows that the client knows the correct password, even though the password itself was never sent. (If you have ever wondered what the default ISAPI filter "md5filt" that is installed with IIS 5.0 is used for, now you know. Integrated Windows Authentication Integrated Windows authentication (formerly known as NTLM authentication and Windows NT Challenge/Response authentication) can use either NTLM or Kerberos V5 authentication and only works with Internet Explorer 2.0 and later. When Internet Explorer attempts to access a protected resource, IIS sends two WWW-Authenticate headers, Negotiate and NTLM. • If Internet Explorer recognizes the Negotiate header, it will choose it because it is listed first. When using Negotiate, the browser will return information for both NTLM and Kerberos. At the server, IIS will use Kerberos if both the client (Internet Explorer 5.0 and later) and server (IIS 5.0 and later) are running Windows 2000 and later, and both are members of the same domain or trusted domains. Otherwise, the server will default to using NTLM. • If Internet Explorer does not understand Negotiate, it will use NTLM. So, which mechanism is used depends upon a negotiation between Internet Explorer and IIS. When used in conjunction with Kerberos v5 authentication, IIS can delegate security credentials among computers running Windows 2000 and later that are trusted and configured for delegation. Delegation enables remote access of resources on behalf of the delegated user. Integrated Windows authentication is the best authentication scheme in an intranet environment where users have Windows domain accounts, especially when using Kerberos. Integrated Windows authentication, like digest authentication, does not pass the user's password across the network. Instead, a hashed value is exchanged. Client Certificate Mapping A certificate is a digitally signed statement that contains information about an entity and the entity's public key, thus binding these two pieces of information together. A trusted organization (or entity) called a Certification Authority (CA) issues a certificate after the CA verifies that the entity is who it says it is. Certificates can contain different types of data. For example, an X.509 certificate includes the format of the certificate, the serial number of the certificate, the algorithm used to sign the certificate, the name of the CA that issued the certificate, the name and public key of the entity requesting the certificate, and the CA's signature. X.509 client certificates simplify authentication for larger user bases because they do not rely on a centralized account database. You can verify a certificate simply by examining the certificate. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsent7/html/vxconIISAuthentication.asp

Where are the IIS log files stored

2009-01-29T23:04:00.000-08:00

Question :Where are the IIS log files stored?
Answer :C:\WINDOWS\system32\Logfiles\W3SVC1 OR c:\winnt\system32\LogFiles\W3SVC1

Can .NET Framework components use the features of Component Services

2009-01-29T23:03:00.000-08:00

Question :Can .NET Framework components use the features of Component Services?
Answer :. In which process does IIS runs (was asking about the EXE file) inetinfo.exe is the Microsoft IIS server running, handling ASP.NET requests among other things. When an ASP.NET request is received (usually a file with .aspx extension), the ISAPI filter aspnet_isapi.dll takes care of it by passing the request to the actual worker process aspnet_wp.exe.

Is it true that COM objects no longer need to be registered on the server

2009-01-29T23:01:00.000-08:00

Question :Is it true that COM objects no longer need to be registered on the server?
Answer :Yes and No. Legacy COM objects still need to be registered on the server before they can be used. COM developed using the new .NET Framework will not need to be registered. Developers will be able to auto-register these objects just by placing them in the 'bin' folder of the application.

What is Pinvoke

2009-01-29T22:54:00.000-08:00

Question :What is Pinvoke?
Answer :Platform invoke is a service that enables managed code to call unmanaged functions implemented in dynamic-link libraries (DLLs), such as those in the Win32 API. It locates and invokes an exported function and marshals its arguments (integers, strings, arrays, structures, and so on) across the interoperation boundary as needed.

Can we copy a COM dll to GAC folder

2009-01-29T22:53:00.000-08:00

Question :Can we copy a COM dll to GAC folder?
Answer :**

Is the COM architecture same as .Net architecture What is the difference between them

2009-01-29T22:51:00.000-08:00

Question :Is the COM architecture same as .Net architecture? What is the difference between them?
Answer :**

What is the new three features of COM+ services, which are not there in COM (MTS)

2009-01-29T22:50:00.000-08:00

Question :What is the new three features of COM+ services, which are not there in COM (MTS)?
Answer :**

What is use of ContextUtil class

2009-01-29T22:49:00.000-08:00

Question :What is use of ContextUtil class?
Answer :ContextUtil is the preferred class to use for obtaining COM+ context information.

How will you register com+ services

2009-01-29T22:48:00.000-08:00

Question :How will you register com+ services?
Answer :The .NET Framework SDK provides the .NET Framework Services Installation Tool (Regsvcs.exe - a command-line tool) to manually register an assembly containing serviced components. You can also access these registration features programmatically with the System.EnterpriseServicesRegistrationHelper class by creating an instance of class RegistrationHelper and using the method InstallAssembly

How CCW and RCW is working

2009-01-29T22:46:00.000-08:00

Question :How CCW and RCW is working?
Answer :**

What is CCW (COM Callable Wrapper)

2009-01-29T22:45:00.000-08:00

Question : What is CCW (COM Callable Wrapper) ?
Answer :A proxy object generated by the common language runtime so that existing COM applications can use managed classes, including .NET Framework classes, transparently.

What is RCW (Runtime Callable Wrappers)

2009-01-29T22:43:00.000-08:00

Question :What is RCW (Runtime Callable Wrappers)?
Answer :The common language runtime exposes COM objects through a proxy called the runtime callable wrapper (RCW). Although the RCW appears to be an ordinary object to .NET clients, its primary function is to marshal calls between a .NET client and a COM object.

Interop Services

2009-01-29T22:40:00.000-08:00

Question :Interop Services?
Answer :The common language runtime provides two mechanisms for interoperating with unmanaged code: • Platform invoke, which enables managed code to call functions exported from an unmanaged library. • COM interop, which enables managed code to interact with COM objects through interfaces. Both platform invoke and COM interop use interop marshaling to accurately move method arguments between caller and callee and back, if required.

What is the use of trace utility

2009-01-29T22:39:00.000-08:00

Question :What is the use of trace utility?
Answer :Using the SOAP Trace Utility The Microsoft® Simple Object Access Protocol (SOAP) Toolkit 2.0 includes a TCP/IP trace utility, MSSOAPT.EXE. You use this trace utility to view the SOAP messages sent by HTTP between a SOAP client and a service on the server. Using the Trace Utility on the Server To see all of a service's messages received from and sent to all clients, perform the following steps on the server. 0. On the server, open the Web Services Description Language (WSDL) file. 1. In the WSDL file, locate the element that corresponds to the service and change the location attribute for this element to port 8080. For example, if the location attribute specifies change this attribute to . 2. Run MSSOAPT.exe. 3. On the File menu, point to New, and either click Formatted Trace (if you don't want to see HTTP headers) or click Unformatted Trace (if you do want to see HTTP headers). 4. In the Trace Setup dialog box, click OK to accept the default values. Using the Trace Utility on the Client To see all messages sent to and received from a service, do the following steps on the client. 5. Copy the WSDL file from the server to the client. 6. Modify location attribute of the element in the local copy of the WSDL document to direct the client to localhost:8080 and make a note of the current host and port. For example, if the WSDL contains , change it to and make note of "MyServer". 7. On the client, run MSSOPT.exe. 8. On the File menu, point to New, and either click Formatted Trace (if you don't want to see HTTP headers) or click Unformatted Trace (if you do want to see HTTP headers). 9. In the Destination host box, enter the host specified in Step 2. 10. In the Destination port box, enter the port specified in Step 2. 11. Click OK.

CAO and SAO

2009-01-29T22:38:00.000-08:00

Question :CAO and SAO?
Answer :Client Activated objects are those remote objects whose Lifetime is directly Controlled by the client. This is in direct contrast to SAO. Where the server, not the client has complete control over the lifetime of the objects. Client activated objects are instantiated on the server as soon as the client request the object to be created. Unlike as SAO a CAO doesn’t delay the object creation until the first method is called on the object. (In SAO the object is instantiated when the client calls the method on the object) 22. singleton and singlecall. Singleton types never have more than one instance at any one time. If an instance exists, all client requests are serviced by that instance. Single Call types always have one instance per client request. The next method invocation will be serviced by a different server instance, even if the previous instance has not yet been recycled by the system.

Though both the .NET Remoting infrastructure and ASP.NET Web services can enable cross-process communication, each is designed to benefit a different

2009-01-29T22:35:00.000-08:00

Question :Though both the .NET Remoting infrastructure and ASP.NET Web services can enable cross-process communication, each is designed to benefit a different target audience. ASP.NET Web services provide a simple programming model and a wide reach. .NET Remoting provides a more complex programming model and has a much narrower reach?
Answer :As explained before, the clear performance advantage provided by TCPChannel-remoting should make you think about using this channel whenever you can afford to do so. If you can create direct TCP connections from your clients to your server and if you need to support only the .NET platform, you should go for this channel. If you are going to go cross-platform or you have the requirement of supporting SOAP via HTTP, you should definitely go for ASP.NET Web services. Both the .NET remoting and ASP.NET Web services are powerful technologies that provide a suitable framework for developing distributed applications. It is important to understand how both technologies work and then choose the one that is right for your application. For applications that require interoperability and must function over public networks, Web services are probably the best bet. For those that require communications with other .NET components and where performance is a key priority, .NET Remoting is the best choice. In short, use Web services when you need to send and receive data from different computing platforms, use .NET Remoting when sending and receiving data between .NET applications. In some architectural scenarios, you might also be able to use.NET Remoting in conjunction with ASP.NET Web services and take advantage of the best of both worlds. The Key difference between ASP.NET webservices and .NET Remoting is how they serialize data into messages and the format they choose for metadata. ASP.NET uses XML serializer for serializing or Marshalling. And XSD is used for Metadata. .NET Remoting relies on System.Runtime.Serialization.Formatter.Binary and System.Runtime.Serialization.SOAPFormatter and relies on .NET CLR Runtime assemblies for metadata.

Difference between web services & remoting

2009-01-29T22:34:00.000-08:00

What is Remoting

2009-01-29T22:33:00.000-08:00

Question :What is Remoting?
Answer :The process of communication between different operating system processes, regardless of whether they are on the same computer. The .NET remoting system is an architecture designed to simplify communication between objects living in different application domains, whether on the same computer or not, and between different contexts, whether in the same application domain or not.

What’s the attribute for webservice method What is the namespace for creating webservice

2009-01-29T22:32:00.000-08:00

Question :What’s the attribute for webservice method? What is the namespace for creating webservice?
Answer :[WebMethod] using System.Web; using System.Web.Services;

How you will protect / secure a web service

2009-01-29T22:28:00.000-08:00

Question :How you will protect / secure a web service?
Answer :For the most part, things that you do to secure a Web site can be used to secure a Web Service. If you need to encrypt the data exchange, you use Secure Sockets Layer (SSL) or a Virtual Private Network to keep the bits secure. For authentication, use HTTP Basic or Digest authentication with Microsoft® Windows® integration to figure out who the caller is.These items cannot: * Parse a SOAP request for valid values * Authenticate access at the Web Method level (they can authenticate at the Web Service level) * Stop reading a request as soon as it is recognized as invalid http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpcontransactionsupportinaspnetwebservices.asp

How to generate proxy class other than .net app and wsdl tool

2009-01-29T22:18:00.000-08:00

Question :How to generate proxy class other than .net app and wsdl tool?
Answer :To access an XML Web service from a client application, you first add a Web reference, which is a reference to an XML Web service. When you create a Web reference, Visual Studio creates an XML Web service proxy class automatically and adds it to your project. This proxy class exposes the methods of the XML Web service and handles the marshalling of appropriate arguments back and forth between the XML Web service and your application. Visual Studio uses the Web Services Description Language (WSDL) to create the proxy. To generate an XML Web service proxy class: * From a command prompt, use Wsdl.exe to create a proxy class, specifying (at a minimum) the URL to an XML Web service or a service description, or the path to a saved service description. Wsdl /language:language /protocol:protocol /namespace:myNameSpace /out:filename /username:username /password:password /domain:domain

How to generate WebService proxy? What is SOAP, WSDL, UDDI and the concept behind Web Services? What are various components of WSDL? What is the use o

2009-01-29T22:17:00.000-08:00

Question :How to generate WebService proxy? What is SOAP, WSDL, UDDI and the concept behind Web Services? What are various components of WSDL? What is the use of WSDL.exe utility?
Answer :SOAP is an XML-based messaging framework specifically designed for exchanging formatted data across the Internet, for example using request and reply messages or sending entire documents. SOAP is simple, easy to use, and completely neutral with respect to operating system, programming language, or distributed computing platform. After SOAP became available as a mechanism for exchanging XML messages among enterprises (or among disparate applications within the same enterprise), a better way was needed to describe the messages and how they are exchanged. The Web Services Description Language (WSDL) is a particular form of an XML Schema, developed by Microsoft and IBM for the purpose of defining the XML message, operation, and protocol mapping of a web service accessed using SOAP or other XML protocol. WSDL defines web services in terms of "endpoints" that operate on XML messages. The WSDL syntax allows both the messages and the operations on the messages to be defined abstractly, so they can be mapped to multiple physical implementations. The current WSDL spec describes how to map messages and operations to SOAP 1.1, HTTP GET/POST, and MIME. WSDL creates web service definitions by mapping a group of endpoints into a logical sequence of operations on XML messages. The same XML message can be mapped to multiple operations (or services) and bound to one or more communications protocols (using "ports"). The Universal Description, Discovery, and Integration (UDDI) framework defines a data model (in XML) and SOAP APIs for registration and searches on business information, including the web services a business exposes to the Internet. UDDI is an independent consortium of vendors, founded by Microsoft, IBM, and Ariba, for the purpose of developing an Internet standard for web service description registration and discovery. Microsoft, IBM, and Ariba also are hosting the initial deployment of a UDDI service, which is conceptually patterned after DNS (the Internet service that translates URLs into TCP addresses). UDDI uses a private agreement profile of SOAP (i.e. UDDI doesn't use the SOAP serialization format because it's not well suited to passing complete XML documents (it's aimed at RPC style interactions). The main idea is that businesses use the SOAP APIs to register themselves with UDDI, and other businesses search UDDI when they want to discover a trading partner, for example someone from whom they wish to procure sheet metal, bolts, or transistors. The information in UDDI is categorized according to industry type and geographical location, allowing UDDI consumers to search through lists of potentially matching businesses to find the specific one they want to contact. Once a specific business is chosen, another call to UDDI is made to obtain the specific contact information for that business. The contact information includes a pointer to the target business's

In a Webservice, need to display 10 rows from a table. So DataReader or DataSet is best choice

2009-01-29T22:16:00.000-08:00

Question :In a Webservice, need to display 10 rows from a table. So DataReader or DataSet is best choice?
Answer :WebService will support only DataSet.

Are Web Services a replacement for other distributed computing platforms

2009-01-29T22:15:00.000-08:00

Question :Are Web Services a replacement for other distributed computing platforms?
Answer :No. Web Services is just a new way of looking at existing implementation platforms.

What is a WebService and what is the underlying protocol used in it?Why Web Services

2009-01-29T22:13:00.000-08:00

Question :What is a WebService and what is the underlying protocol used in it?Why Web Services?
Answer :Web Services are applications delivered as a service on the Web. Web services allow for programmatic access of business logic over the Web. Web services typically rely on XML-based protocols, messages, and interface descriptions for communication and access. Web services are designed to be used by other programs or applications rather than directly by end user. Programs invoking a Web service are called clients. SOAP over HTTP is the most commonly used protocol for invoking Web services. There are three main uses of Web services. 1. Application integration Web services within an intranet are commonly used to integrate business applications running on disparate platforms. For example, a .NET client running on Windows 2000 can easily invoke a Java Web service running on a mainframe or Unix machine to retrieve data from a legacy application. 2. Business integration Web services allow trading partners to engage in e-business leveraging the existing Internet infrastructure. Organizations can send electronic purchase orders to suppliers and receive electronic invoices. Doing e-business with Web services means a low barrier to entry because Web services can be added to existing applications running on any platform without changing legacy code. 3. Commercial Web services focus on selling content and business services to clients over the Internet similar to familiar Web pages. Unlike Web pages, commercial Web services target applications not humans as their direct users. Continental Airlines exposes flight schedules and status Web services for travel Web sites and agencies to use in their applications. Like Web pages, commercial Web services are valuable only if they expose a valuable service or content. It would be very difficult to get customers to pay you for using a Web service that creates business charts with the customers? data. Customers would rather buy a charting component (e.g. COM or .NET component) and install it on the same machine as their application. On the other hand, it makes sense to sell real-time weather information or stock quotes as a Web service. Technology can help you add value to your services and explore new markets, but ultimately customers pay for contents and/or business services, not for technology

What’s different about switch statements in C#

2009-01-29T22:05:00.000-08:00

Question :What’s different about switch statements in C#?
Answer :No fall-throughs allowed. Unlike the C++ switch statement, C# does not support an explicit fall through from one case label to another. If you want, you can use goto a switch-case, or goto default. case 1: cost += 25; break; case 2: cost += 25; goto case 1;

Is goto statement supported in C# How about Java

2009-01-29T22:04:00.000-08:00

Question :Is goto statement supported in C#? How about Java?
Answer :Gotos are supported in C#to the fullest. In Java goto is a reserved keyword that provides absolutely no functionality.

Will it go to finally block if there is no exception happened

2009-01-29T22:03:00.000-08:00

Question :Will it go to finally block if there is no exception happened?
Answer :Yes. The finally block is useful for cleaning up any resources allocated in the try block. Control is always passed to the finally block regardless of how the try block exits.

What is close method How its different from Finalize & Dispose

2009-01-29T22:02:00.000-08:00

Question :What is close method? How its different from Finalize & Dispose?
Answer :**

What is the difference between Finalize and Dispose (Garbage collection)

2009-01-29T22:00:00.000-08:00

Question :What is the difference between Finalize and Dispose (Garbage collection)?
Answer :Class instances often encapsulate control over resources that are not managed by the runtime, such as window handles (HWND), database connections, and so on. Therefore, you should provide both an explicit and an implicit way to free those resources. Provide implicit control by implementing the protected Finalize Method on an object (destructor syntax in C# and the Managed Extensions for C++). The garbage collector calls this method at some point after there are no longer any valid references to the object. In some cases, you might want to provide programmers using an object with the ability to explicitly release these external resources before the garbage collector frees the object. If an external resource is scarce or expensive, better performance can be achieved if the programmer explicitly releases resources when they are no longer being used. To provide explicit control, implement the Dispose method provided by the IDisposable Interface. The consumer of the object should call this method when it is done using the object. Dispose can be called even if other references to the object are alive. Note that even when you provide explicit control by way of Dispose, you should provide implicit cleanup using the Finalize method. Finalize provides a backup to prevent resources from permanently leaking if the programmer fails to call Dispose.

Destructor and finalize

2009-01-29T21:43:00.000-08:00

Question :Destructor and finalize ?
Answer :Generally in C++ the destructor is called when objects gets destroyed. And one can explicitly call the destructors in C++. And also the objects are destroyed in reverse order that they are created in. So in C++ you have control over the destructors. In C# you can never call them, the reason is one cannot destroy an object. So who has the control over the destructor (in C#)? it's the .Net frameworks Garbage Collector (GC). GC destroys the objects only when necessary. Some situations of necessity are memory is exhausted or user explicitly calls System.GC.Collect() method. Points to remember: 1. Destructors are invoked automatically, and cannot be invoked explicitly. 2. Destructors cannot be overloaded. Thus, a class can have, at most, one destructor. 3. Destructors are not inherited. Thus, a class has no destructors other than the one, which may be declared in it. 4. Destructors cannot be used with structs. They are only used with classes. 5. An instance becomes eligible for destruction when it is no longer possible for any code to use the instance. 6. Execution of the destructor for the instance may occur at any time after the instance becomes eligible for destruction. 7. When an instance is destructed, the destructors in its inheritance chain are called, in order, from most derived to least derived. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconfinalizemethodscdestructors.asp

Overloaded constructor will call default constructor internally

2009-01-29T21:42:00.000-08:00

Question :Overloaded constructor will call default constructor internally?
Answer :(no)

I have 3 overloaded constructors in my class. In order to avoid making instance of the class do I need to make all constructors to private

2009-01-29T21:41:00.000-08:00

Question :I have 3 overloaded constructors in my class. In order to avoid making instance of the class do I need to make all constructors to private?
Answer :(Yes)

What is Private Constructor and it’s use Can you create instance of a class which has Private Constructor

2009-01-29T21:39:00.000-08:00

Question :What is Private Constructor? and it’s use? Can you create instance of a class which has Private Constructor?
Answer :When a class declares only private instance constructors, it is not possible for classes outside the program to derive from the class or to directly create instances of it. (Except Nested classes) Make a constructor private if: - You want it to be available only to the class itself. For example, you might have a special constructor used only in the implementation of your class' Clone method. - You do not want instances of your component to be created. For example, you may have a class containing nothing but Shared utility functions, and no instance data. Creating instances of the class would waste memory.

Difference between type constructor and instance constructor What is static constructor, when it will be fired And what is its use

2009-01-29T21:33:00.000-08:00

Question :Difference between type constructor and instance constructor? What is static constructor, when it will be fired? And what is its use?
Answer :(Class constructor method is also known as type constructor or type initializer) Instance constructor is executed when a new instance of type is created and the class constructor is executed after the type is loaded and before any one of the type members is accessed. (It will get executed only 1st time, when we call any static methods/fields in the same class.) Class constructors are used for static field initialization. Only one class constructor per type is permitted, and it cannot use the vararg (variable argument) calling convention. A static constructor is used to initialize a class. It is called automatically to initialize the class before the first instance is created or any static members are referenced.

What is the difference between a private assembly and a shared assembly

2009-01-29T04:48:00.000-08:00

Question :What is the difference between a private assembly and a shared assembly?
Answer :Location and visibility: A private assembly is normally used by a single application, and is stored in the application's directory, or a sub-directory beneath. A shared assembly is normally stored in the global assembly cache, which is a repository of assemblies maintained by the .NET runtime. Shared assemblies are usually libraries of code which many applications will find useful, e.g. the .NET framework classes. Versioning: The runtime enforces versioning constraints only on shared assemblies, not on private assemblies.

What is an assembly

2009-01-29T04:47:00.000-08:00

Question :What is an assembly?
Answer :An assembly is sometimes described as a logical .EXE or .DLL, and can be an application (with a main entry point) or a library. An assembly consists of one or more files (dlls, exes, html files etc), and represents a group of resources, type definitions, and implementations of those types. An assembly may also contain references to other assemblies. These resources, types and references are described in a block of data called a manifest. The manifest is part of the assembly, thus making the assembly self-describing. An important aspect of assemblies is that they are part of the identity of a type. The identity of a type is the assembly that houses it combined with the type name. This means, for example, that if assembly A exports a type called T, and assembly B exports a type called T, the .NET runtime sees these as two completely different types. Furthermore, don't get confused between assemblies and namespaces - namespaces are merely a hierarchical way of organising type names. To the runtime, type names are type names, regardless of whether namespaces are used to organise the names. It's the assembly plus the typename (regardless of whether the type name belongs to a namespace) that uniquely indentifies a type to the runtime. Assemblies are also important in .NET with respect to security - many of the security restrictions are enforced at the assembly boundary. Finally, assemblies are the unit of versioning in .NET - more on this below.

What is reflection

2009-01-29T04:46:00.000-08:00

Question :What is reflection?
Answer :All .NET compilers produce metadata about the types defined in the modules they produce. This metadata is packaged along with the module (modules in turn are packaged together in assemblies), and can be accessed by a mechanism called reflection. The System.Reflection namespace contains classes that can be used to interrogate the types for a module/assembly.Using reflection to access .NET metadata is very similar to using ITypeLib/ITypeInfo to access type library data in COM, and it is used for similar purposes - e.g. determining data type sizes for marshaling data across context/process/machine boundaries.Reflection can also be used to dynamically invoke methods (see System.Type.InvokeMember), or even create types dynamically at run-time (see System.Reflection.Emit.TypeBuilder). Assemblies

What does 'managed' mean in the .NET context

2009-01-29T04:45:00.000-08:00

Question :What does 'managed' mean in the .NET context?
Answer :The term 'managed' is the cause of much confusion. It is used in various places within .NET, meaning slightly different things. Managed code: The .NET framework provides several core run-time services to the programs that run within it - for example exception handling and security. For these services to work, the code must provide a minimum level of information to the runtime. Such code is called managed code. All C# and Visual Basic.NET code is managed by default. VS7 C++ code is not managed by default, but the compiler can produce managed code by specifying a command-line switch (/com+). Managed data: This is data that is allocated and de-allocated by the .NET runtime's garbage collector. C# and VB.NET data is always managed. VS7 C++ data is unmanaged by default, even when using the /com+ switch, but it can be marked as managed using the __gc keyword. Managed classes: This is usually referred to in the context of Managed Extensions (ME) for C++. When using ME C++, a class can be marked with the __gc keyword. As the name suggests, this means that the memory for instances of the class is managed by the garbage collector, but it also means more than that. The class becomes a fully paid-up member of the .NET community with the benefits and restrictions that brings. An example of a benefit is proper interop with classes written in other languages - for example, a managed C++ class can inherit from a VB class. An example of a restriction is that a managed class can only inherit from one base class.

What is C#

2009-01-29T04:44:00.000-08:00

Question :What is C#?
Answer :C# is a new language designed by Microsoft to work with the .NET framework. In their "Introduction to C#" whitepaper, Microsoft describe C# as follows: "C# is a simple, modern, object oriented, and type-safe programming language derived from C and C++. C# (pronounced C sharp) is firmly planted in the C and C++ family tree of languages, and will immediately be familiar to C and C++ programmers. C# aims to combine the high productivity of Visual Basic and the raw power of C++." Substitute 'Java' for 'C#' in the quote above, and you'll see that the statement still works pretty well :-).

What is IL

2009-01-29T04:43:00.000-08:00

Question :What is IL?
Answer :IL = Intermediate Language. Also known as MSIL (Microsoft Intermediate Language) or CIL (Common Intermediate Language). All .NET source code (of any language) is compiled to IL. The IL is then converted to machine code at the point where the software is installed, or at run-time by a Just-In-Time (JIT) compiler.

What is the CLR

2009-01-29T04:41:00.000-08:00

Question :What is the CLR?
Answer :CLR = Common Language Runtime. The CLR is a set of standard resources that (in theory) any .NET program can take advantage of, regardless of programming language. Robert Schmidt (Microsoft) lists the following CLR resources in his MSDN PDC# article:Object-oriented programming model (inheritance, polymorphism, exception handling, garbage collection)Security model, Type system , All .NET base classes, Many .NET framework classes, Development, debugging, and profiling tools, Execution and code management IL-to-native translators and optimizers

Will the .NET Framework go through a standardisation process

2009-01-29T04:20:00.000-08:00

Question :Will the .NET Framework go through a standardisation process?
Answer :From http://msdn.microsoft.com/net/ecma/: "On December 13, 2001, the ECMA General Assembly ratified the C# and common language infrastructure (CLI) specifications into international standards. The ECMA standards will be known as ECMA-334 (C#) and ECMA-335 (the CLI)." Basic terminology

What languages does the .NET Framework support

2009-01-29T04:19:00.000-08:00

Question :What languages does the .NET Framework support?
Answer :MS provides compilers for C#, C++, VB and JScript. Other vendors have announced that they intend to develop .NET compilers for languages such as COBOL, Eiffel, Perl, Smalltalk and Python.

What platforms does the .NET Framework run on

2009-01-29T04:18:00.000-08:00

Question :What platforms does the .NET Framework run on?
Answer :The runtime supports Windows XP, Windows 2000, NT4 SP6a and Windows ME/98. Windows 95 is not supported. Some parts of the framework do not work on all platforms - for example, ASP.NET is only supported on Windows XP and Windows 2000. Windows 98/ME cannot be used for development. IIS is not supported on Windows XP Home Edition, and so cannot be used to host ASP.NET. However, the ASP.NET Web Matrix web server does run on XP Home. The Mono project is attempting to implement the .NET framework on Linux.

When was the first version of .NET released

2009-01-29T04:17:00.001-08:00

Question :When was the first version of .NET released?
Answer :The final version of the 1.0 SDK and runtime was made publicly available around 6pm PST on 15-Jan-2002. At the same time, the final version of Visual Studio.NET was made available to MSDN subscribers.

When was .NET announced

2009-01-29T04:16:00.000-08:00

Question :When was .NET announced?
Answer :Bill Gates delivered a keynote at Forum 2000, held June 22, 2000, outlining the .NET 'vision'. The July 2000 PDC had a number of sessions on .NET technology, and delegates were given CDs containing a pre-release version of the .NET framework/SDK and Visual Studio.NET.

Does .NET only apply to people building web-sites

2009-01-29T04:13:00.000-08:00

Question :Does .NET only apply to people building web-sites?
Answer :No. If you write any Windows software (using ATL/COM, MFC, VB, or even raw Win32), .NET may offer a viable alternative (or addition) to the way you do things currently. Of course, if you do develop web sites, then .NET has lots to interest you - not least ASP.NET.

CAO and SAO

2009-01-29T03:37:00.000-08:00

Difference between web services & remoting

2009-01-29T03:36:00.000-08:00

Question :Difference between web services & remoting?
Answer :ASP.NET Web Services .NET Remoting Protocol Can be accessed only over HTTP Can be accessed over any protocol (including TCP, HTTP, SMTP and so on) State Management Web services work in a stateless environment Provide support for both stateful and stateless environments through Singleton and SingleCall objects Type System Web services support only the datatypes defined in the XSD type system, limiting the number of objects that can be serialized. Using binary communication, .NET Remoting can provide support for rich type system Interoperability Web services support interoperability across platforms, and are ideal for heterogeneous environments. .NET remoting requires the client be built using .NET, enforcing homogenous environment. Reliability Highly reliable due to the fact that Web services are always hosted in IIS Can also take advantage of IIS for fault isolation. If IIS is not used, application needs to provide plumbing for ensuring the reliability of the application. Extensibility Provides extensibility by allowing us to intercept the SOAP messages during the serialization and deserialization stages. Very extensible by allowing us to customize the different components of the .NET remoting framework. Ease-of-Programming Easy-to-create and deploy. Complex to program. Though both the .NET Remoting infrastructure and ASP.NET Web services can enable cross-process communication, each is designed to benefit a different target audience. ASP.NET Web services provide a simple programming model and a wide reach. .NET Remoting provides a more complex programming model and has a much narrower reach. As explained before, the clear performance advantage provided by TCPChannel-remoting should make you think about using this channel whenever you can afford to do so. If you can create direct TCP connections from your clients to your server and if you need to support only the .NET platform, you should go for this channel. If you are going to go cross-platform or you have the requirement of supporting SOAP via HTTP, you should definitely go for ASP.NET Web services. Both the .NET remoting and ASP.NET Web services are powerful technologies that provide a suitable framework for developing distributed applications. It is important to understand how both technologies work and then choose the one that is right for your application. For applications that require interoperability and must function over public networks, Web services are probably the best bet. For those that require communications with other .NET components and where performance is a key priority, .NET Remoting is the best choice. In short, use Web services when you need to send and receive data from different computing platforms, use .NET Remoting when sending and receiving data between .NET applications. In some architectural scenarios, you might also be able to use.NET Remoting in conjunction with ASP.NET Web services and take advantage of the best of both worlds. The Key difference between ASP.NET webservices and .NET Remoting is how they serialize data into messages and the format they choose for metadata. ASP.NET uses XML serializer for serializing or Marshalling. And XSD is used for Metadata. .NET Remoting relies on System.Runtime.Serialization.Formatter.Binary and System.Runtime.Serialization.SOAPFormatter and relies on .NET CLR Runtime assemblies for metadata.

What is Remoting

2009-01-29T03:35:00.000-08:00

What’s the attribute for webservice method? What is the namespace for creating webservice

2009-01-29T03:34:00.000-08:00

Question :What’s the attribute for webservice method? What is the namespace for creating webservice?
Answer :[WebMethod] using System.Web; using System.Web.Services;

How you will protect / secure a web service

2009-01-29T03:27:00.000-08:00

Question :How you will protect / secure a web service?
Answer :For the most part, things that you do to secure a Web site can be used to secure a Web Service. If you need to encrypt the data exchange, you use Secure Sockets Layer (SSL) or a Virtual Private Network to keep the bits secure. For authentication, use HTTP Basic or Digest authentication with Microsoft® Windows® integration to figure out who the caller is. these items cannot: •Parse a SOAP request for valid values •Authenticate access at the Web Method level (they can authenticate at the Web Service level) •Stop reading a request as soon as it is recognized as invalid

How to generate proxy class other than .net app and wsdl tool

2009-01-29T03:18:00.000-08:00

Question :How to generate proxy class other than .net app and wsdl tool?
Answer :To access an XML Web service from a client application, you first add a Web reference, which is a reference to an XML Web service. When you create a Web reference, Visual Studio creates an XML Web service proxy class automatically and adds it to your project. This proxy class exposes the methods of the XML Web service and handles the marshalling of appropriate arguments back and forth between the XML Web service and your application. Visual Studio uses the Web Services Description Language (WSDL) to create the proxy. To generate an XML Web service proxy class: •From a command prompt, use Wsdl.exe to create a proxy class, specifying (at a minimum) the URL to an XML Web service or a service description, or the path to a saved service description. Wsdl /language:language /protocol:protocol /namespace:myNameSpace /out:filename /username:username /password:password /domain:domain

How to generate WebService proxy? What is SOAP, WSDL, UDDI and the concept behind Web Services? What are various components of WSDL? What is the use o

2009-01-29T03:17:00.001-08:00

In a Webservice, need to display 10 rows from a table. So DataReader or DataSet is best choice

2009-01-29T03:15:00.000-08:00

Question :In a Webservice, need to display 10 rows from a table. So DataReader or DataSet is best choice?
Answer :WebService will support only DataSet.

Are Web Services a replacement for other distributed computing platforms

2009-01-29T03:14:00.000-08:00

Question :Are Web Services a replacement for other distributed computing platforms?
Answer :No. Web Services is just a new way of looking at existing implementation platforms.

What is a WebService and what is the underlying protocol used in it?Why Web Services

2009-01-29T03:13:00.000-08:00

Question :What is a WebService and what is the underlying protocol used in it?Why Web Services?
Answer :Web Services are applications delivered as a service on the Web. Web services allow for programmatic access of business logic over the Web. Web services typically rely on XML-based protocols, messages, and interface descriptions for communication and access. Web services are designed to be used by other programs or applications rather than directly by end user. Programs invoking a Web service are called clients. SOAP over HTTP is the most commonly used protocol for invoking Web services. There are three main uses of Web services. 1.Application integration Web services within an intranet are commonly used to integrate business applications running on disparate platforms. For example, a .NET client running on Windows 2000 can easily invoke a Java Web service running on a mainframe or Unix machine to retrieve data from a legacy application. 2.Business integration Web services allow trading partners to engage in e-business leveraging the existing Internet infrastructure. Organizations can send electronic purchase orders to suppliers and receive electronic invoices. Doing e-business with Web services means a low barrier to entry because Web services can be added to existing applications running on any platform without changing legacy code. 3.Commercial Web services focus on selling content and business services to clients over the Internet similar to familiar Web pages. Unlike Web pages, commercial Web services target applications not humans as their direct users. Continental Airlines exposes flight schedules and status Web services for travel Web sites and agencies to use in their applications. Like Web pages, commercial Web services are valuable only if they expose a valuable service or content. It would be very difficult to get customers to pay you for using a Web service that creates business charts with the customers? data. Customers would rather buy a charting component (e.g. COM or .NET component) and install it on the same machine as their application. On the other hand, it makes sense to sell real-time weather information or stock quotes as a Web service. Technology can help you add value to your services and explore new markets, but ultimately customers pay for contents and/or business services, not for technology

Is it possible for me to change my aspx file extension to some other name

2009-01-29T03:07:00.000-08:00

Question :Is it possible for me to change my aspx file extension to some other name?
Answer :Yes. Open IIS->Default Website -> Properties Select HomeDirectory tab Click on configuration button Click on add. Enter aspnet_isapi details (C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\aspnet_isapi.dll GET,HEAD,POST,DEBUG) Open machine.config(C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\CONFIG) & add new extension under tag

What is smart navigation

2009-01-29T03:06:00.000-08:00

Question :What is smart navigation?
Answer :When a page is requested by an Internet Explorer 5 browser, or later, smart navigation enhances the user's experience of the page by performing the following: •eliminating the flash caused by navigation. •persisting the scroll position when moving from page to page. •persisting element focus between navigations. •retaining only the last page state in the browser's history. Smart navigation is best used with ASP.NET pages that require frequent postbacks but with visual content that does not change dramatically on return. Consider this carefully when deciding whether to set this property to true. Set the SmartNavigation attribute to true in the @ Page directive in the .aspx file. When the page is requested, the dynamically generated class sets this property.

What are the different modes for the sessionstates in the web.config file

2009-01-29T03:05:00.000-08:00

Question :What are the different modes for the sessionstates in the web.config file?
Answer :Off Indicates that session state is not enabled. Inproc Indicates that session state is stored locally. StateServer Indicates that session state is stored on a remote server. SQLServer Indicates that session state is stored on the SQL Server.

What is the use of sessionstate tag in the web.config file

2009-01-29T03:04:00.000-08:00

Question :What is the use of sessionstate tag in the web.config file?
Answer :Configuring session state: Session state features can be configured via the section in a web.config file. To double the default timeout of 20 minutes, you can add the following to the web.config file of an application:

What is the use of web.config? Difference between machine.config and Web.config

2009-01-29T03:01:00.000-08:00

Question :What is the use of web.config? Difference between machine.config and Web.config?
Answer :ASP.NET configuration files are XML-based text files--each named web.config--that can appear in any directory on an ASP.NET Web application server. Each web.config file applies configuration settings to the directory it is located in and to all virtual child directories beneath it. Settings in child directories can optionally override or modify settings specified in parent directories. The root configuration file--WinNT\Microsoft.NET\Framework\\config\machine.config—provides default configuration settings for the entire machine. ASP.NET configures IIS to prevent direct browser access to web.config files to ensure that their values cannot become public (attempts to access them will cause ASP.NET to return 403: Access Forbidden). At run time ASP.NET uses these web.config configuration files to hierarchically compute a unique collection of settings for each incoming URL target request (these settings are calculated only once and then cached across subsequent requests; ASP.NET automatically watches for file changes and will invalidate the cache if any of the configuration files change).

Any alternative to avoid name collisions other then Namespaces.

2009-01-29T02:59:00.000-08:00

Question :Any alternative to avoid name collisions other then Namespaces. A scenario that two namespaces named N1 and N2 are there both having the same class say A. now in another class i ve written using N1;using N2; and i am instantiating class A in this class. Then how will u avoid name collisions?
Answer :using alias Eg: using MyAlias = MyCompany.Proj.Nested;

How to do Caching in ASP

2009-01-29T02:58:00.000-08:00

Question :How to do Caching in ASP?
Answer :VaryByParam value Description none One version of page cached (only raw GET) * n versions of page cached based on query string and/or POST body v1 n versions of page cached based on value of v1 variable in query string or POST body v1;v2 n versions of page cached based on value of v1 and v2 variables in query string or POST body The OutputCache directive supports several other cache varying options •VaryByHeader - maintain separate cache entry for header string changes (UserAgent, UserLanguage, etc.) •VaryByControl - for user controls, maintain separate cache entry for properties of a user control •VaryByCustom - can specify separate cache entries for browser types and version or provide a custom GetVaryByCustomString method in HttpApplicationderived class

Asp.net - How to find last error which occurred

2009-01-29T02:57:00.000-08:00

Question :Asp.net - How to find last error which occurred?
Answer :A: Server.GetLastError(); [C#] Exception LastError; String ErrMessage; LastError = Server.GetLastError(); if (LastError != null) ErrMessage = LastError.Message; else ErrMessage = "No Errors"; Response.Write("Last Error = " + ErrMessage);

What is SQL injection

2009-01-29T02:55:00.000-08:00

Question :What is SQL injection?
Answer :An SQL injection attack "injects" or manipulates SQL code by adding unexpected SQL to a query. Many web pages take parameters from web user, and make SQL query to the database. Take for instance when a user login, web page that user name and password and make SQL query to the database to check if a user has valid name and password. Username: ' or 1=1 --- Password: [Empty] This would execute the following query against the users table: select count(*) from users where userName='' or 1=1 --' and userPass=''

How do you implement postback with a text box What is postback and usestate

2009-01-29T02:54:00.000-08:00

Question :How do you implement postback with a text box? What is postback and usestate?
Answer :Make AutoPostBack property to true

Which two properties are there on every validation control? ControlToValidate, ErrorMessage how do you use css in asp.net

2009-01-29T02:49:00.000-08:00

Question :Which two properties are there on every validation control? ControlToValidate, ErrorMessage How do you use css in asp.net?
Answer :Within the section of an HTML document that will use these styles, add a link to this external CSS style sheet that follows this form: MyStyles.css is the name of your external CSS style sheet.

What are validator? Name the Validation controls in asp.net? How do u disable them? Will the asp.net validators run in server side or client side? How

2009-01-29T02:46:00.000-08:00

Question :What are validator? Name the Validation controls in asp.net? How do u disable them? Will the asp.net validators run in server side or client side? How do you do ClA set of server controls included with ASP.NET that test user input in HTML and Web server controls for programmer-defined requirements. Validation controls perform input checking in server code. If the user is working with a browser that supports DHTML, the validation controls can also perform validation ("EnableClientScript" property set to true/false) using client script. The following validation controls are available in asp.net: RequiredFieldValidator Control, CompareValidator Control, RangeValidator Control, RegularExpressionValidator Control, CustomValidator Control, ValidationSummary Control. ient-side validation in .Net? How to disable validator control by client side JavaScript?
Answer :

How do you specify whether your data should be passed as Query string and Forms (Mainly about POST and GET)

2009-01-29T02:45:00.000-08:00

Question :How do you specify whether your data should be passed as Query string and Forms (Mainly about POST and GET)?
Answer :Through attribute tag of form tag.

What are the different authentication modes in the .NET environment

2009-01-29T02:43:00.000-08:00

Question :What are the different authentication modes in the .NET environment?
Answer :="WindowsFormsPassportNone"> ="name" loginUrl="url" protection="AllNoneEncryptionValidation" timeout="30" path="/" > requireSSL="truefalse" slidingExpiration="truefalse"> ="ClearSHA1MD5"> ="username" password="password"/> internal"/> Attribute Option Description Mode Controls the default authentication mode for an application. Windows Specifies Windows authentication as the default authentication mode. Use this mode when using any form of Microsoft Internet Information Services (IIS) authentication: Basic, Digest, Integrated Windows authentication (NTLM/Kerberos), or certificates. Forms Specifies ASP.NET forms-based authentication as the default authentication mode. Passport Specifies Microsoft Passport authentication as the default authentication mode. None Specifies no authentication. Only anonymous users are expected or applications can handle events to provide their own authentication.

What is Role-Based security

2009-01-29T02:42:00.000-08:00

Question :What is Role-Based security?
Answer :A role is a named set of principals that have the same privileges with respect to security (such as a teller or a manager). A principal can be a member of one or more roles. Therefore, applications can use role membership to determine whether a principal is authorized to perform a requested action.

Which ASP.NET configuration options are supported in the ASP.NET implementation on the shared web hosting platform

2009-01-29T02:41:00.000-08:00

Question :Which ASP.NET configuration options are supported in the ASP.NET implementation on the shared web hosting platform?
Answer : Many of the ASP.NET configuration options are not configurable at the site, application or subdirectory level on the shared hosting platform. Certain options can affect the security, performance and stability of the server and, therefore cannot be changed. The following settings are the only ones that can be changed in your site’s web.config file (s): browserCaps clientTarget pages customErrors globalization authorization authentication webControls webServices

Explain the differences between Server-side and Client-side code

2009-01-29T02:40:00.000-08:00

Question :Explain the differences between Server-side and Client-side code?
Answer :Server side code will process at server side & it will send the result to client. Client side code (javascript) will execute only at client side.

When maintaining session through Sql server, what is the impact of Read and Write operation on Session objects will performance degrade

2009-01-29T02:39:00.000-08:00

Question :When maintaining session through Sql server, what is the impact of Read and Write operation on Session objects? will performance degrade?
Answer :Maintaining state using database technology is a common practice when storing user-specific information where the information store is large. Database storage is particularly useful for maintaining long-term state or state that must be preserved even if the server must be restarted.

What are the disadvantages of view state / what are the benefits

2009-01-29T02:37:00.000-08:00

Question :What are the disadvantages of view state / what are the benefits?
Answer :Automatic view-state management is a feature of server controls that enables them to repopulate their property values on a round trip (without you having to write any code). This feature does impact performance, however, since a server control's view state is passed to and from the server in a hidden form field. You should be aware of when view state helps you and when it hinders your page's performance.

What is State Management in .Net and how many ways are there to maintain a state in .Net What is view state

2009-01-29T02:36:00.000-08:00

Question :What is State Management in .Net and how many ways are there to maintain a state in .Net? What is view state?
Answer :Web pages are recreated each time the page is posted to the server. In traditional Web programming, this would ordinarily mean that all information associated with the page and the controls on the page would be lost with each round trip. To overcome this inherent limitation of traditional Web programming, the ASP.NET page framework includes various options to help you preserve changes — that is, for managing state. The page framework includes a facility called view state that automatically preserves property values of the page and all the controls on it between round trips. However, you will probably also have application-specific values that you want to preserve. To do so, you can use one of the state management options. Client-Based State Management Options: View State Hidden Form Fields Cookies Query Strings Server-Based State Management Options Application State Session State Database Support

How you will handle session when deploying application in more than a server? Describe session handling in a webfarm, how does it work and what are th

2009-01-29T02:34:00.000-08:00

Question :How you will handle session when deploying application in more than a server? Describe session handling in a webfarm, how does it work and what are the limits?
Answer :By default, ASP.NET will store the session state in the same process that processes the request, just as ASP does. Additionally, ASP.NET can store session data in an external process, which can even reside on another machine. To enable this feature: •Start the ASP.NET state service, either using the Services snap-in or by executing "net start aspnet_state" on the command line. The state service will by default listen on port 42424. To change the port, modify the registry key for the service: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\aspnet_state\Parameters\Port •Set the mode attribute of the section to "StateServer". •Configure the stateConnectionString attribute with the values of the machine on which you started aspnet_state. The following sample assumes that the state service is running on the same machine as the Web server ("localhost") and uses the default port (42424): Note that if you try the sample above with this setting, you can reset the Web server (enter iisreset on the command line) and the session state value will persist.

What is cookie less session How it works

2009-01-29T02:33:00.000-08:00

Question :What is cookie less session? How it works?
Answer :By default, ASP.NET will store the session state in the same process that processes the request, just as ASP does. If cookies are not available, a session can be tracked by adding a session identifier to the URL. This can be enabled by setting the following:

Difference between ASP Session and ASP.NET Session

2009-01-29T02:32:00.000-08:00

Question :Difference between ASP Session and ASP.NET Session?
Answer :asp.net session supports cookie less session & it can span across multiple servers.

Application and Session Events

2009-01-29T02:30:00.000-08:00

Question :Application and Session Events ?
Answer :The ASP.NET page framework provides ways for you to work with events that can be raised when your application starts or stops or when an individual user's session starts or stops: •Application events are raised for all requests to an application. For example, Application_BeginRequest is raised when any Web Forms page or XML Web service in your application is requested. This event allows you to initialize resources that will be used for each request to the application. A corresponding event, Application_EndRequest, provides you with an opportunity to close or otherwise dispose of resources used for the request. •Session events are similar to application events (there is a Session_OnStart and a Session_OnEnd event), but are raised with each unique session within the application. A session begins when a user requests a page for the first time from your application and ends either when your application explicitly closes the session or when the session times out. You can create handlers for these types of events in the Global.asax file.

What is the difference between Web User Control and Web Custom Control

2009-01-29T02:29:00.000-08:00

Question :What is the difference between Web User Control and Web Custom Control?
Answer :Custom Controls Web custom controls are compiled components that run on the server and that encapsulate user-interface and other related functionality into reusable packages. They can include all the design-time features of standard ASP.NET server controls, including full support for Visual Studio design features such as the Properties window, the visual designer, and the Toolbox. There are several ways that you can create Web custom controls: •You can compile a control that combines the functionality of two or more existing controls. For example, if you need a control that encapsulates a button and a text box, you can create it by compiling the existing controls together. •If an existing server control almost meets your requirements but lacks some required features, you can customize the control by deriving from it and overriding its properties, methods, and events. •If none of the existing Web server controls (or their combinations) meet your requirements, you can create a custom control by deriving from one of the base control classes. These classes provide all the basic functionality of Web server controls, so you can focus on programming the features you need. If none of the existing ASP.NET server controls meet the specific requirements of your applications, you can create either a Web user control or a Web custom control that encapsulates the functionality you need. The main difference between the two controls lies in ease of creation vs. ease of use at design time. Web user controls are easy to make, but they can be less convenient to use in advanced scenarios. You develop Web user controls almost exactly the same way that you develop Web Forms pages. Like Web Forms, user controls can be created in the visual designer, they can be written with code separated from the HTML, and they can handle execution events. However, because Web user controls are compiled dynamically at run time they cannot be added to the Toolbox, and they are represented by a simple placeholder glyph when added to a page. This makes Web user controls harder to use if you are accustomed to full Visual Studio .NET design-time support, including the Properties window and Design view previews. Also, the only way to share the user control between applications is to put a separate copy in each application, which takes more maintenance if you make changes to the control. Web custom controls are compiled code, which makes them easier to use but more difficult to create; Web custom controls must be authored in code. Once you have created the control, however, you can add it to the Toolbox and display it in a visual designer with full Properties window support and all the other design-time features of ASP.NET server controls. In addition, you can install a single copy of the Web custom control in the global assembly cache and share it between applications, which makes maintenance easier. Web user controls Web custom controls Easier to create Harder to create Limited support for consumers who use a visual design tool Full visual design tool support for consumers A separate copy of the control is required in each application Only a single copy of the control is required, in the global assembly cache Cannot be added to the Toolbox in Visual Studio Can be added to the Toolbox in Visual Studio Good for static layout Good for dynamic layout

What are server controls

2009-01-29T02:27:00.000-08:00

Question :What are server controls?
Answer :ASP.NET server controls are components that run on the server and encapsulate user-interface and other related functionality. They are used in ASP.NET pages and in ASP.NET code-behind classes.

Order of events in an asp.net page Control Execution Lifecycle

2009-01-29T02:19:00.000-08:00

Question :Order of events in an asp.net page? Control Execution Lifecycle?
Answer :Phase What a control needs to do Method or event to override Initialize Initialize settings needed during the lifetime of the incoming Web request. Init event (OnInit method) Load view state At the end of this phase, the ViewState property of a control is automatically populated as described in Maintaining State in a Control. A control can override the default implementation of the LoadViewState method to customize state restoration. LoadViewState method Process postback data Process incoming form data and update properties accordingly. LoadPostData method (if IPostBackDataHandler is implemented) Load Perform actions common to all requests, such as setting up a database query. At this point, server controls in the tree are created and initialized, the state is restored, and form controls reflect client-side data. Load event (OnLoad method) Send postback change notifications Raise change events in response to state changes between the current and previous postbacks. RaisePostDataChangedEvent method (if IPostBackDataHandler is implemented) Handle postback events Handle the client-side event that caused the postback and raise appropriate events on the server. RaisePostBackEvent method(if IPostBackEventHandler is implemented) Prerender Perform any updates before the output is rendered. Any changes made to the state of the control in the prerender phase can be saved, while changes made in the rendering phase are lost. PreRender event (OnPreRender method) Save state The ViewState property of a control is automatically persisted to a string object after this stage. This string object is sent to the client and back as a hidden variable. For improving efficiency, a control can override the SaveViewState method to modify the ViewState property. SaveViewState method Render Generate output to be rendered to the client. Render method Dispose Perform any final cleanup before the control is torn down. References to expensive resources such as database connections must be released in this phase. Dispose method Unload Perform any final cleanup before the control is torn down. Control authors generally perform cleanup in Dispose and do not handle this event. UnLoad event (On UnLoad method) Note To override an EventName event, override the OnEventName method (and call base.OnEventName)

Asp.net and asp – differences

2009-01-29T02:17:00.000-08:00

Question :Asp.net and asp – differences?
Answer :Code Render Block Code Declaration Block Compiled Request/Response Event Driven Object Oriented - Constructors/Destructors, Inheritance, overloading.. Exception Handling - Try, Catch, Finally Down-level Support Cultures User Controls In-built client side validation Session - weren't transferable across servers It can span across servers, It can survive server crashes, can work with browsers that don't support cookies built on top of the window & IIS, it was always a separate entity & its functionality was limited. its an integral part of OS under the .net framework. It shares many of the same objects that traditional applications would use, and all .net objects are available for asp.net's consumption. Garbage Collection Declare variable with datatype In built graphics support Cultures

What is method to get XML and schema from Dataset

2009-01-29T02:16:00.000-08:00

Question :What is method to get XML and schema from Dataset?
Answer :getXML () and get Schema ()

Differences between dataset.clone and dataset.copy

2009-01-29T02:13:00.000-08:00

Question :Differences between dataset.clone and dataset.copy?
Answer :Clone - Copies the structure of the DataSet, including all DataTable schemas, relations, and constraints. Does not copy any data. Copy - Copies both the structure and data for this DataSet.

In how many ways we can retrieve table records count? How to find the count of records in a dataset

2009-01-29T02:12:00.000-08:00

Question :In how many ways we can retrieve table records count? How to find the count of records in a dataset?
Answer :foreach(DataTable thisTable in myDataSet.Tables){ // For each row, print the values of each column. foreach(DataRow myRow in thisTable.Rows){

What happens when we issue Dataset.ReadXml command

2009-01-29T02:11:00.000-08:00

Question :What happens when we issue Dataset.ReadXml command?
Answer :Reads XML schema and data into the DataSet.

Explain different methods and Properties of DataReader which you have used in your project

2009-01-29T02:09:00.000-08:00

Question :Explain different methods and Properties of DataReader which you have used in your project?
Answer :1. Read 2. GetString 3. GetInt32 while (myReader.Read()) Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1)); myReader.Close();

Which method do you invoke on the DataAdapter control to load your generated dataset with data

2009-01-29T02:07:00.000-08:00

Question :Which method do you invoke on the DataAdapter control to load your generated dataset with data?
Answer :Fill()

Difference between DataReader and DataAdapter / DataSet and DataAdapter

2009-01-29T02:05:00.000-08:00

Question :Difference between DataReader and DataAdapter / DataSet and DataAdapter?
Answer :You can use the ADO.NET DataReader to retrieve a read-only, forward-only stream of data from a database. Using the DataReader can increase application performance and reduce system overhead because only one row at a time is ever in memory. After creating an instance of the Command object, you create a DataReader by calling Command.ExecuteReader to retrieve rows from a data source, as shown in the following example. SqlDataReader myReader = myCommand.ExecuteReader(); You use the Read method of the DataReader object to obtain a row from the results of the query. while (myReader.Read()) Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1)); myReader.Close(); The DataSet is a memory-resident representation of data that provides a consistent relational programming model regardless of the data source. It can be used with multiple and differing data sources, used with XML data, or used to manage data local to the application. The DataSet represents a complete set of data including related tables, constraints, and relationships among the tables. The methods and objects in a DataSet are consistent with those in the relational database model. The DataSet can also persist and reload its contents as XML and its schema as XML Schema definition language (XSD) schema. The DataAdapter serves as a bridge between a DataSet and a data source for retrieving and saving data. The DataAdapter provides this bridge by mapping Fill, which changes the data in the DataSet to match the data in the data source, and Update, which changes the data in the data source to match the data in the DataSet. If you are connecting to a Microsoft SQL Server database, you can increase overall performance by using the SqlDataAdapter along with its associated SqlCommand and SqlConnection. For other OLE DB-supported databases, use the DataAdapter with its associated OleDbCommand and OleDbConnection objects.

What are the different namespaces used in the project to connect the database What data providers available in .net to connect to database

2009-01-29T02:03:00.000-08:00

Question :What are the different namespaces used in the project to connect the database? What data providers available in .net to connect to database?
Answer :•System.Data.OleDb – classes that make up the .NET Framework Data Provider for OLE DB-compatible data sources. These classes allow you to connect to an OLE DB data source, execute commands against the source, and read the results. •System.Data.SqlClient – classes that make up the .NET Framework Data Provider for SQL Server, which allows you to connect to SQL Server 7.0, execute commands, and read results. The System.Data.SqlClient namespace is similar to the System.Data.OleDb namespace, but is optimized for access to SQL Server 7.0 and later. •System.Data.Odbc - classes that make up the .NET Framework Data Provider for ODBC. These classes allow you to access ODBC data source in the managed space. •System.Data.OracleClient - classes that make up the .NET Framework Data Provider for Oracle. These classes allow you to access an Oracle data source in the managed space.

Difference between OLEDB Provider and SqlClient

2009-01-29T02:02:00.000-08:00

Question :Difference between OLEDB Provider and SqlClient ?
Answer :SQLClient .NET classes are highly optimized for the .net / sqlserver combination and achieve optimal results. The SqlClient data provider is fast. It's faster than the Oracle provider, and faster than accessing database via the OleDb layer. It's faster because it accesses the native library (which automatically gives you better performance), and it was written with lots of help from the SQL Server team.

What are relation objects in dataset and how & where to use them

2009-01-29T01:58:00.000-08:00

Question :What are relation objects in dataset and how & where to use them?
Answer :In a DataSet that contains multiple DataTable objects, you can use DataRelation objects to relate one table to another, to navigate through the tables, and to return child or parent rows from a related table. Adding a DataRelation to a DataSet adds, by default, a UniqueConstraint to the parent table and a ForeignKeyConstraint to the child table. The following code example creates a DataRelation using two DataTable objects in a DataSet. Each DataTable contains a column named CustID, which serves as a link between the two DataTable objects. The example adds a single DataRelation to the Relations collection of the DataSet. The first argument in the example specifies the name of the DataRelation being created. The second argument sets the parent DataColumn and the third argument sets the child DataColumn. custDS.Relations.Add("CustOrders", custDS.Tables["Customers"].Columns["CustID"], custDS.Tables["Orders"].Columns["CustID"]); OR private void CreateRelation() { // Get the DataColumn objects from two DataTable objects in a DataSet. DataColumn parentCol; DataColumn childCol; // Code to get the DataSet not shown here. parentCol = DataSet1.Tables["Customers"].Columns["CustID"]; childCol = DataSet1.Tables["Orders"].Columns["CustID"]; // Create DataRelation. DataRelation relCustOrder; relCustOrder = new DataRelation("CustomersOrders", parentCol, childCol); // Add the relation to the DataSet. DataSet1.Relations.Add(relCustOrder); }

How would u connect to database using .NET

2009-01-29T01:56:00.000-08:00

Question :How would u connect to database using .NET?
Answer :SqlConnection nwindConn = new SqlConnection("Data Source=localhost; Integrated Security=SSPI;" + "Initial Catalog=northwind"); nwindConn.Open();