.NET Questions

After you add a LINQ to SQL Classes item to a project and open the O/R Designer, the empty design surface represents an empty DataContext class ready to be configured. The DataContext class is a LINQ to SQL class that acts as a conduit between a SQL Server database and the LINQ to SQL entity classes mapped to that database. This class contains the connection string information and the methods for connecting to a database and manipulating the data in the database. It is configured with connection information provided by the first item that is dragged onto the design surface.

A keyword that specifies that types in a particular nemespace can be referred to without requiring their full qualified type names. 'using' reserved word always come with namespaces. eg. using systems so because of this useful classes supplied by Microsoft which are contained by system namespace are availble for user.

AJAX uses four technologies, which are as follows:

       => JavaScript

       => XMLHttpRequest

       => Document Object Model (DOM)

       => Extensible HTML (XHTML) and Cascading Style Sheets (CSS)

       => Windows Installer

       => ClickOnce

       => XCOPY

       => Copy Web Site

       => Publish Web Site tool

Assemblies are the basic building blocks required for any application to function in the .NET realm. They are partially compiled code libraries that form the fundamental unit of deployment, versioning, activation scoping, reuse, and security. Typically, assemblies provide a collection of types and resources that work together to form a logical unit of functionality. They are the smallest deployable units of code in .NET. Compared to the executable files assemblies are far more reliable, more secure, and easy to manage. An assembly contains a lot more than the Microsoft Intermediate Language (MSIL) code that is compiled and run by the Common Language Runtime (CLR). In other words, you can say that an assembly is a set of one or more modules and classes compiled in MSIL, and metadata that describes the assembly itself, as well as the functionalities of the assembly classes.

Variables that are defined in a C# program belong to two major categories: value type and reference type. The variables that are based on value type contain a value that is either allocated on a stack or allocated in-line in a structure. The variables that are based on reference types store the memory address of a variable, which in turn stores the value and are allocated on the heap. The variables that are based on value types have their own copy of data and therefore operations done on one variable do not affect other variables. The reference-type variables reflect the changes made in the referring variables.

CompareValidator  allows checking if data of one control match with other control

LINQ is a programming model that is the composition of general-purpose standard query operators that allow you to work with data, regardless of the data source in any .NET based programming language. It is the name given to a set of technologies based on the integration of query capabilities into any .NET language.