Directives -Master

@Master directive belongs to Master Pages that is .master files.
Master pages are use to mitigate redundant coding & programming.So, Master pages are use to create for integrating common code in all pages such as header footer,navigation , banners which are most common features in any web applications.

This directive
Defines master page–specific (.master file) attributes that are used by the ASP.NET page parser and compiler.

Its Attributes are

AutoEventWireup

To hook up event with control explicitly if it set false else event auto-wiring is enabled; The default is true.

ClassName

Specifies the class name for the class that is automatically generated from the markup and compiled when the master page is processed. This value can be any valid class name and can include a namespace.

CodeFile

Specifies the name of a separate file that contains a partial class with the event handlers and other master page–specific code.

CompilationMode

Specifies whether to compile an ASP.NET master page at run time. Options are Always to always compile the page; Auto, if ASP.NET is to avoid compiling the page, if possible; and Never, to never compile the page or control. The default is Always.

CompilerOptions
Provides a string containing compiler options to use to compile the page. In C# and Microsoft Visual Basic, this is a sequence of compiler command-line switches.

Debug

Indicates whether to compile the master page with debug symbols. true, to compile with debug symbols; otherwise, false.

Description

Provides a text description of the master page. This value is ignored by the ASP.NET parser.

EnableTheming

Indicates whether the appearance of the master page and of controls on the master page can be modified, if a theme is applied. true if a theme can be applied; otherwise, false. The default is true. Setting the EnableTheming attribute is primarily useful when a page theme is defined in the Web.config file and applies to all pages, by default.

EnableViewState

Indicates whether view state is maintained across page requests. true to maintain view state; otherwise, false. The default is true.

Explicit

Determines whether the page is compiled using the Visual Basic Option Explicit mode. true indicates that the Visual Basic explicit compile option is enabled and that all variables must be declared using a Dim, Private, Public, or ReDim statement; otherwise, false. The default is false.

Inherits

Specifies a code-behind class for the page to inherit. This can be any class derived from the MasterPage class.

Language

Specifies the language used when compiling all inline rendering (<% %> and <%= %>) and code declaration blocks within the page. Values can represent any language that is supported by the .NET Framework, including VB (Visual Basic), C#, and JScript.

LinePragmas

Determines whether the runtime should generate pragmas in the generated code.

MasterPageFile

Specifies the .master file that acts as a master page for a master page. The MasterPageFile attribute is used in a master page when defining a child master page in a nested master-page scenario.

Src

Specifies the source file name of the code-behind class to dynamically compile when the page is requested. You can choose to include programming logic for your page either in a code-behind class or in a Code Declaration Blocks in the .aspx file.

Strict

Specifies whether to compile the page using the Visual Basic Option Strict mode. true if Option Strict is enabled; otherwise, false. The default is false.
The Strict attribute is ignored by languages other than Visual Basic.

WarningLevel

It Specifies the compiler warning level at which you want the compiler to abort compilation for the page. Its Possible values are from 0 through 4.