Export (0) Print
Expand All

IHttpHandlerFactory.GetHandler Method

Returns an instance of a class that implements the IHttpHandler interface.

Namespace:  System.Web
Assembly:  System.Web (in System.Web.dll)

IHttpHandler GetHandler(
	HttpContext context,
	string requestType,
	string url,
	string pathTranslated
)

Parameters

context
Type: System.Web.HttpContext

An instance of the HttpContext class that provides references to intrinsic server objects (for example, Request, Response, Session, and Server) used to service HTTP requests.

requestType
Type: System.String

The HTTP data transfer method (GET or POST) that the client uses.

url
Type: System.String

The RawUrl of the requested resource.

pathTranslated
Type: System.String

The PhysicalApplicationPath to the requested resource.

Return Value

Type: System.Web.IHttpHandler
A new IHttpHandler object that processes the request.

The following code example demonstrates how to create custom handler objects in response to a client request. The example has two parts:

  • A handler factory class.

  • A Web.config file excerpt.

The first part of the example shows how to create custom handler objects in response to a client request for a page named either abc.aspx or xyz.aspx. The handler factory class named hwf creates the appropriate handler object depending on the page requested.

// Name this C# file HandlerFactoryTest.cs and compile it with the 
// command line: csc /t:Library /r:System.Web.dll HandlerFactoryTest.cs. 
// Copy HandlerFactoryTest.dll to your \bin directory. 

namespace test
{
   using System;
   using System.Web;

   // Factory class that creates a handler object based on a request  
   // for either abc.aspx or xyz.aspx as specified in the Web.config file. 
   public class MyFactory : IHttpHandlerFactory
   {
      [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
      public virtual IHttpHandler GetHandler(HttpContext context, 
                                             String requestType, 
                                             String url, 
                                             String pathTranslated)
      {
         String fname = url.Substring(url.LastIndexOf('/')+1);
         String cname = fname.Substring(0, fname.IndexOf('.'));
         String className = "test." + cname;

         Object h = null;

         // Try to create the handler object. 
         try 
         {
            // Create the handler by calling class abc or class xyz.
            h = Activator.CreateInstance(Type.GetType(className));
         }
         catch(Exception e)
         {
            throw new HttpException("Factory couldn't create instance " +
                                    "of type " + className, e);
         }
         return (IHttpHandler)h;
      }

      // This is a must override method. 
      public virtual void ReleaseHandler(IHttpHandler handler)
      {
      }
   }

   // Class definition for abc.aspx handler. 
   public class abc : IHttpHandler
   {
      public virtual void ProcessRequest(HttpContext context)
      {
         context.Response.Write("<html><body>");
         context.Response.Write("<p>ABC Handler</p>\n");
         context.Response.Write("</body></html>");
      }

      public virtual bool IsReusable
      {
         get { return true; }
      }
   }

   // Class definition for xyz.aspx handler. 
   public class xyz : IHttpHandler
   {
      public virtual void ProcessRequest(HttpContext context)
      {
         context.Response.Write("<html><body>");
         context.Response.Write("<p>XYZ Handler</p>\n");
         context.Response.Write("</body></html>");
      }

      public virtual bool IsReusable
      {
         get { return true; }
      }
   }
}

/*
______________________________________________________________

To use the handler factory, use the following lines in a 
Web.config file.

<configuration>
   <system.web>
      <httpHandlers>
         <add verb="*" path="abc.aspx" type="test.MyFactory,HandlerFactoryTest" />
         <add verb="*" path="xyz.aspx" type="test.MyFactory,HandlerFactoryTest" />
      </httpHandlers>     
   </system.web>
</configuration>
*/
   

The second part of the example shows a Web.config file excerpt. To use the above handler factory, add the following lines to the Web.config file.

<configuration> 
  <system.web> 
    <httpHandlers> 
      <add verb="*" path="abc.aspx" type="test.MyFactory,HandlerFactoryTest" /> 
      <add verb="*" path="xyz.aspx" type="test.MyFactory,HandlerFactoryTest" /> 
    </httpHandlers> 
  </system.web>
</configuration> 

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft