Marshal.AddRef(IntPtr) Method

Definition

Namespace:

System.Runtime.InteropServices

Assembly:

System.Runtime.InteropServices.dll

Source:

Marshal.cs

Increments the reference count on the specified interface.

public:
 static int AddRef(IntPtr pUnk);

public static int AddRef (IntPtr pUnk);

static member AddRef : nativeint -> int

Public Shared Function AddRef (pUnk As IntPtr) As Integer

Parameters

pUnk

IntPtr

nativeint

The interface reference count to increment.

Returns

Int32

The new value of the reference count on the pUnk parameter.

Remarks

The common language runtime manages the reference count of a COM object for you, making it unnecessary to use this method directly. In rare cases, such as testing a custom marshaler, you might find it necessary to manipulate an object's lifetime manually. After calling AddRef, you must decrement the reference count by using a method such as Marshal.Release. Do not rely on the return value of AddRef, as it can sometimes be unstable.

You can call Marshal.GetComInterfaceForObject, Marshal.GetIUnknownForObject, or Marshal.GetIDispatchForObject to obtain an IntPtr value that represents an IUnknown interface pointer. You can also use these methods and the AddRef method on managed objects to obtain the COM interfaces represented by the managed object's COM callable wrapper. If you are not familiar with the details of this wrapper type, see COM Callable Wrapper.

See also

• Release(IntPtr)
• QueryInterface(IntPtr, Guid, IntPtr)
• GetComInterfaceForObject(Object, Type)
• GetIUnknownForObject(Object)
• GetIDispatchForObject(Object)
• IUnknown::AddRef