Httpmodule, filtering and interfering with ASP. NET event processing)

HttpmoduleThroughHttpapplicationObject event processingHTTPProcess MPs queue impact. These events must beHttpmoduleOfInitMethod, including:Beginrequest,Authenticaterequest,Authorizerequest,Resolverequestcache,Acquirerequeststate,Prerequesthandlerexecute,Postrequesthandlerexecute,Releaserequeststate,Updaterequestcache,Endrequest.

Using System;
Using System. Web;
Using System. Security. Principal;

Namespace Xumh
{
///   <Summary>
///  
/// Implement httpmodule:
/// 1. Write class implementation ihttpmodule
/// 2. compile it as a Class Library: CSC/T: Library testhttpmodule. CS
/// 3. To make your web page use it, you must register it in Web. config.
///   <Httpmodules>  
///   <Add name = "xumhhttpmodule" type = "xumh. testhttpmodule, testhttpmodule"/>
///   <Add name = "whatever name" type = "Space. Class Name, DLL file without extension/>
///   </Httpmodules>
/// 4. This httpmodule handles registration. To facilitate testing, anonymous access needs to be disabled as follows:
/// <Authorization>
/// <Deny users = "? "/>
/// </Authorization>
///   </Summary>
Public   Class Testhttpmodule: ihttpmodule
{
Public   Void Dispose ()
{
Throw   New Notimplementedexception ();
}

Public VoidInit (httpapplication context)
{//We can register many events.
Context. authenticaterequest+ = NewEventhandler (context_authenticaterequest );
}

// Authenticaterequest
Void Context_authenticaterequest ( Object Sender, eventargs E)
{
Httpapplication app = (Httpapplication) sender;
Httpcontext Context = (Httpcontext) app. context;
If (App. request [ " Userid " ] =   Null   | App. request [ " Password " ] = Null )
{
Context. response. Write ( " The user name or password is empty. Verification Failed! " );
App. response. End ();
}
//
String Userid = App. request [ " Userid " ]. Tostring ();
String Password = App. request [ " Password " ]. Tostring ();
String [] Roles = Authenticateandgetroles (userid, password ); // Get user permission list
If (Roles = Null   | Roles. getlength ( 0 ) = 0 )
{
App. response. Write ( " Incorrect username or password. Verification Failed! " );
App. completerequest (); // Terminate an HTTP request
}
Genericidentity identity =   New Genericidentity (userid, " Customauthentication " );
Context. User =   New Genericprincipal (identity, roles );

}

// Authenticateandgetroles
Private   String [] Authenticateandgetroles ( String Userid, String Password)
{
String [] Roles =   Null ;
If (Userid. Equals ( " Xuminghui " ) && Password. Equals ( " 1234 " ))
{
Roles =   New   String [ 1 ];
Roles [ 0 ] =   " Administrator " ;
}
Else   If (Userid. Equals ( " Haohao " ) && Password. Equals ( " 1017 " ))
{
Roles =   New   String [ 1 ];
Roles [ 0 ] =   " User " ;
}
Return Roles;
}

}

}

For detailed procedures, see