WebRequest.RegisterPrefix Method

Registers a WebRequest descendant for the specified URI.

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

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



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


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

Return Value

true if registration is successful; otherwise, false.

Exception typeCondition


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

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

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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