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Marshal.GetDelegateForFunctionPointer Method (IntPtr, Type)

Converts an unmanaged function pointer to a delegate.

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

static member GetDelegateForFunctionPointer : 
        ptr:IntPtr * 
        t:Type -> Delegate

Parameters

ptr
Type: System.IntPtr

The unmanaged function pointer to be converted.

t
Type: System.Type

The type of the delegate to be returned.

Return Value

Type: System.Delegate
A delegate instance that can be cast to the appropriate delegate type.

ExceptionCondition
ArgumentException

The t parameter is not a delegate or is generic.

ArgumentNullException

The ptr parameter is a null reference (Nothing in Visual Basic).

-or-

The t parameter is a null reference (Nothing in Visual Basic).

In versions 1.0 and 1.1 of the .NET Framework, it was possible to pass a delegate representing a managed method to unmanaged code as a function pointer, allowing the unmanaged code to call the managed method through the function pointer. It was also possible for the unmanaged code to pass that function pointer back to the managed code, and the pointer was resolved properly to the underlying managed method.

In the .NET Framework 2.0 and later versions, you can use the GetDelegateForFunctionPointer and GetFunctionPointerForDelegate methods to marshal delegates in both directions. With GetDelegateForFunctionPointer, ptr is imported as a System.IntPtr. A System.IntPtr can be obtained for a managed delegate by calling GetFunctionPointerForDelegate and passed as a parameter; it can then be called from inside the unmanaged method. Note that the parameter marshaler can also marshal function pointers to delegates in the .NET Framework 2.0 and later versions.

The GetDelegateForFunctionPointer method has the following restrictions:

  • Generics are not supported in interop scenarios.

  • You cannot pass an invalid function pointer to this method.

  • You can use this method only for pure unmanaged function pointers.

  • You cannot use this method with function pointers obtained through C++ or from the GetFunctionPointer method.

  • You cannot use this method to create a delegate from a function pointer to another managed delegate.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

  • SecurityCriticalAttribute 

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

Windows Phone 8.1, Windows Phone 8, 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.

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