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Socket.DuplicateAndClose Method

Duplicates the socket reference for the target process, and closes the socket for this process.

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

public SocketInformation DuplicateAndClose(
	int targetProcessId


Type: System.Int32

The ID of the target process where a duplicate of the socket reference is created.

Return Value

Type: System.Net.Sockets.SocketInformation
The socket reference to be passed to the target process.


targetProcessID is not a valid process id.


Duplication of the socket reference failed.

The target process should use Socket to create the duplicate socket instance.

If you call the Socket constructor multiple times with the same byte array as the argument for each call, you will create multiple managed Sockets with the same underlying socket. This practice is strongly discouraged.

If the process creating the socket uses asynchronous methods (BeginReceive or BeginSend), the process must first set the UseOnlyOverlappedIO property to true; otherwise, the socket is bound to the completion port of the creating process, which may cause an ArgumentNullException to be thrown on the target process.

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

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