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Marshal.GetUniqueObjectForIUnknown Method

Creates a unique Runtime Callable Wrapper (RCW) object for a given IUnknown interface.

Namespace:  System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

public static Object GetUniqueObjectForIUnknown(
	IntPtr unknown


Type: System.IntPtr
A managed pointer to an IUnknown interface.

Return Value

Type: System.Object
A unique RCW for the specified IUnknown interface.

The GetUniqueObjectForIUnknown method ensures that you receive a unique RCW, because it does not match an IUnknown pointer to an existing object. Use this method when you have to create a unique RCW that is not impacted by other code that calls the ReleaseComObject method.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

  • SecurityCriticalAttribute 

    requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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