GetIUnknownForObjectInContext Method
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Marshal.GetIUnknownForObjectInContext Method

Note: This method is new in the .NET Framework version 2.0.

Returns an IUnknown interface from a managed object, if the caller is in the same context as that object.

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

public static IntPtr GetIUnknownForObjectInContext (
	Object o
)
public static IntPtr GetIUnknownForObjectInContext (
	Object o
)
public static function GetIUnknownForObjectInContext (
	o : Object
) : IntPtr

Parameters

o

The object whose IUnknown interface is requested.

Return Value

The IUnknown pointer for the o parameter, or a null reference (Nothing in Visual Basic) if the caller is not in the same context as the specified object.

This method is the same as GetIUnknownForObject except that it returns a null reference (Nothing in Visual Basic) if the caller is not in the same context as the object.

NoteNote

This method uses SecurityAction.LinkDemand to prevent it from being called from untrusted code; only the immediate caller is required to have SecurityPermissionAttribute.UnmanagedCode permission. If your code can be called from partially trusted code, do not pass user input to Marshal class methods without validation. For important limitations on using the LinkDemand member, see Demand vs. LinkDemand.

The following code example demonstrates how to retrieve an IUnknown interface for a managed object using the GetIUnknownForObjectInContext method.

using System;
using System.Runtime.InteropServices;

class Program
{

    static void Run()
    {

        // Create an int object
        int obj = 1;

        Console.WriteLine("Calling Marshal.GetIUnknownForObjectInContext...");

        // Get the IUnKnown pointer for the Integer object
        IntPtr pointer = Marshal.GetIUnknownForObjectInContext(obj);

        Console.WriteLine("Calling Marshal.Release...");

        // Always call Marshal.Release to decrement the reference count.
        Marshal.Release(pointer);
    }

    static void Main(string[] args)
    {
        Run();
    }
}

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0

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