Featues of ASP.NET 2.0

ASP.NET 2.0 improves ASP.NET by adding several new features.
Design goals for ASP.NET 2.0:

• Increase productivity by removing 70% of the code
• Use the same controls for all types of devices
• Provides a faster and better web server platform
• Simplify the administration of web applications

Some of the features in ASP.NET 2.0 are:

• Master Pages, Themes, and Web Parts
• Standard controls for navigation
• Standard controls for security
• Roles, personalization and internationalization services
• Improved and simplified data access controls
• Full support for XML standard like , XHTML, XML, and WSDL
• Improved compilation and deployment(installation)
• Improved site management
• New and improved development tools
  

Client Side Validation

ASP.NET automatically adds JavaScript code for client side validation.In this case, when the user clicks a CausesValidation button, the same error message will appear without the page needing to be submitted and returned from the server.This increase the representation of your web page.
However, even if the page validates successfully on the client side,ASP.NET still revalidates it when it's received at the server.This is because it's easy for an experienced user to circumvent client side validation. For example, a malicious user might delete the block of JavaScript validation. For example, a malicious user might delete the block of JavaScript validation code and continue working with the page.By performing the validation at both ends,ASP.NET makes sure your application can be responsive as possible while also remaining secure.

Server Side Validation

You can use the validator controls to verify a page automatically when the user submits it or manually in your code.The first approach is the most common.
When using automatic validation,the user receive a normal page and begins to fill in the input controls. When finished, the user clicks a button to submit the page.Every button has a causes Validation property, which can be set to true or false.What happens when the user clicks the button depends on the value of the CausesValidation property.

• If CausesValidation is false, ASP.NET will ignore the validation controls,the page will be posted back,and your event-handling code will run normally.
• If CausesValidation is true(the default), ASP.NET will automatically validate the page when the user clicks the button. It does this by performing the validation for each control on the page. If any control fails to validate, ASP.NET will return the page with some error information,depending on your setting.Your click event-handling code may or may not be executed-meaning you'll have to specifically check in the event handler whether the page is valid.
  

What is methods?

Methods are the most basic building block you can use to organize your code. Essentially,a method is a named grouping of one or more lines of code.Ideally,each method will perform a distinct,logical task.By breaking your code down into methods, you not only simplify your life,but you also make it easier to organize your code into classes and step into the world of object oriented programming.
When you declare a method in C#,the first part of the declaration specifies the data type of the return value,and the second part indicates the method name.If your method doesn't return any information,you should use the void keyword instead of a data type at the beginning of the declaration.
Here are two examples-one method that doesn't return anything and one that does:

// This method doesn't return any information.
void MyMethodNoReturnedData()
{
// Code goes here.
}

// This method returns an integer.
int MyMethodReturnsData()
{
// Return the number 10.
return 10;
}

Method Overloading?

Method overloading, which allows you to create more than one method with the same name,but with a different set of parameters. When you call the method ,the CLR automatically choose the correct version by examining the parameters you supply.
This technique allows you to collect different versions of several methods together. For example, you might allow a database search that returns an array of Product object representing records in the database.Rather than create three methods with different names depending on the criteria,suchasGetProducts(),
GetProductsInCategory(),and GetActiveProducts(),you could create three versions of the GetProducts() methods. Each method would have the same name but a different signature ,meaning it would require different parameters.This example provides two overloaded versions for the GetProductPrice() method:

private decimal GetProductPrice(int ID)
{
// Code here
}
private decimal GetProductPrice(string name)
{
// Code here
}

What is document object?

The document object is the most important information source for most Javascript program , and information about many aspects of the HTML document are represented by the properties found here. It allows you to update a document, which is being displayed and to access the components available in the loaded document.
The document object has several properties. For example the write() method, which you have learn in the earlier section is very useful, and allows the program to generate HTML that will be inserted in the document when it is displayed. Various properties are given below:

• forms[] :- An array of form objects, one for each
  and
  in the document. The number of forms in the document can be determine using the statement form.length.
• images[] :- An array of image objects,one for each embedded image. The number of images can be determine using images.length statement.
• links[] :- An array of link objects, one for each hypertext link in the document. The number of link objects can be determine using links.length statement.
  

What is Class Library?

• A class library is the loaded into the application domain that use it.
• When application use a class library that class library is a loaded into a application. e.g. If a application use a class library A and class library B is use into class library A then both A and B are loaded into the application.