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WebRequest.RegisterPrefix Method

Registers a WebRequest descendant for the specified URI.

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

public static function RegisterPrefix(
	prefix : String, 
	creator : IWebRequestCreate
) : boolean


Type: System.String

The complete URI or URI prefix that the WebRequest descendant services.

Type: System.Net.IWebRequestCreate

The create method that the WebRequest calls to create the WebRequest descendant.

Return Value

Type: System.Boolean
true if registration is successful; otherwise, false.


prefix is a null reference (Nothing in Visual Basic)


creator is a null reference (Nothing in Visual Basic).

The RegisterPrefix method registers WebRequest descendants to service requests. WebRequest descendants are typically registered to handle a specific protocol, such HTTP or FTP, but can be registered to handle a request to a specific server or path on a server.

Duplicate prefixes are not allowed. RegisterPrefix returns false if an attempt is made to register a duplicate prefix.


The HttpWebRequest class is registered to service requests for HTTP and HTTPS schemes by default. Attempts to register a different WebRequest descendant for these schemes will fail.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0