.NET Interview Questions with Answers Page IV

From freshersonline.com

Interview Question Home

1. What is "Common Type System" (CTS)?

CTS defines all of the basic types that can be used in the .NET Framework and the operations

performed on those type.

All this time we have been talking about language interoperability, and .NET Class Framework.

None of this is possible without all the language sharing the same data types. What this means

is that an int should mean the same in VB, VC++, C# and all other .NET compliant languages.

This is achieved through introduction of Common Type System (CTS).

2.What is "Common Language Specification" (CLS)?

CLS is the collection of the rules and constraints that every language (that seeks to achieve .NET

compatibility) must follow. It is a subsection of CTS and it specifies how it shares and extends one

another libraries.

3. What is "Common Language Runtime" (CLR)?

CLR is .NET equivalent of Java Virtual Machine (JVM). It is the runtime that converts a MSIL code into

the host machine language code, which is then executed appropriately. The CLR is the execution engine for

.NET Framework applications. It provides a number of services, including:

- Code management (loading and execution)

- Application memory isolation

- Verification of type safety

- Conversion of IL to native code.

- Access to metadata (enhanced type information)

- Managing memory for managed objects

- Enforcement of code access security

- Exception handling, including cross-language exceptions

- Interoperation between managed code, COM objects, and pre-existing DLL's (unmanaged code and data)

- Automation of object layout

- Support for developer services (profiling, debugging, and so on).

4. Using COM Component in .Net

As most of you know that .Net does not encourage the development of COM components and provides a

different solution to making reusable components through Assemblies. But, there are a lot of COM

components present which our .Net application might need to use. Fortunately, .Net provides an

extremely simple approach to achieve this. This is achieved by using ‘Wrapper Classes’ and ‘Proxy Components’.

.Net wraps the COM component into .Net assembly technically called ‘Runtime Callable Wrapper’ or RCW.

Then u can call and use your COM component just as a .Net (or C#, if u are using C#) Assembly.

5. What is a Web Service?

A web service is a software component that exposes itself through the open communication channels of

the Internet. Applications running on remote machines, on potentially different platforms, can access

these components in a language and platform-independent manner. A Web Service is a group of functions,

packaged together for use in a common framework throughout a network.

6. What is a formatter?

A formatter is an object that is responsible for encoding and serializing data into messages on one end,

and deserializing and decoding messages into data on the other end.

7. What are channels in .NET Remoting?

Channels represent the objects that transfer the other serialized objects from one application domain to

another and from one computer to another, as well as one process to another on the same box. A channel

must exist before an object can be transferred.

8.What’s a Windows process?

It’s an application that’s running and had been allocated memory.

9. What’s SingleCall activation mode used for?

If the server object is instantiated for responding to just one single request, the request should be

made in SingleCall mode.

10. How do you trigger the Paint event in System.Drawing?

Invalidate the current form, the OS will take care of repainting. The Update method forces the repaint.

11.What is the base class of .NET?

Base class provides a base set of methods that all derived classes can use

12. What is "Microsoft Intermediate Language" (MSIL)?

A .NET programming language (C#, VB.NET, J# etc.) does not compile into executable code; instead it compiles

into an intermediate code called Microsoft Intermediate Language (MSIL). As a programmer one need not worry

about the syntax of MSIL - since our source code in automatically converted to MSIL. The MSIL code is then send

to the CLR (Common Language Runtime) that converts the code to machine language, which is, then run on the host

machine. MSIL is similar to Java Byte code. MSIL is the CPU-independent instruction set into which .NET Framework

programs are compiled. It contains instructions for loading, storing, initializing, and calling methods on objects.

Combined with metadata and the common type system, MSIL allows for true cross- language integration Prior to execution,

MSIL is converted to machine code. It is not interpreted.

13. How is meant by DLL ?

A DLL (Dynamic Link Library) is a file that can be loaded and executed by programs dynamically. Basically it’s an external

code repository for programs. Since usually several different programs reuse the same DLL instead of having that code in

their own file, this dramatically reduces required storage space. A synonym for a DLL would be library.

14. What is the base class of Button control?

Listing from visual studio .net > Button Class

System.Object

System.MarshalByRefObject

System.ComponentModel.Component

System.Windows.Forms.Control

System.Windows.Forms.ButtonBase

System.Windows.Forms.Button