Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

Marshal.GetObjectForIUnknown Method

Returns an instance of a type that represents a COM object by a pointer to its IUnknown interface.

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

public static Object GetObjectForIUnknown(
	IntPtr pUnk
)

Parameters

pUnk
Type: System.IntPtr

A pointer to the IUnknown interface.

Return Value

Type: System.Object
An object that represents the specified unmanaged COM object.

This method wraps IUnknown in a managed object. This has the effect of incrementing the reference count of the COM component. The reference count will be decremented when the runtime performs garbage collection on the managed object that represents the COM object.

The pUnk parameter represents an IUnknown interface pointer; however, because all COM interfaces derive directly or indirectly from IUnknown, you can pass any COM interface to this method. The object returned by GetObjectForIUnknown is a Runtime Callable Wrapper, which the common language runtime manages as it does any other managed object. The type of this wrapper is often a generic System.__ComObject type, which is a hidden type used when the wrapper type is ambiguous. You can still make late-bound calls to such a generic type as long as the COM object implements the IDispatch interface. Likewise, you can cast the returned object to an appropriate COM interface.

For an object to be wrapped with a specific managed class type (and not a generic wrapper type), you must adhere to the following requirements:

Alternatively, you can avoid these requirements and still get an object that is wrapped with a specific managed class type by using the Marshal.GetTypedObjectForIUnknown method.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

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

Portable Class Library

Supported in: Portable Class Library

  • SecurityCriticalAttribute 

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

Show:
© 2015 Microsoft