Target Property
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GCHandle.Target Property


Gets or sets the object this handle represents.

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

public object Target {

Property Value

Type: System.Object

The object this handle represents.

Exception Condition

The handle was freed, or never initialized.

The following example shows an App class that creates a handle to a managed object using the GCHandle.Alloc method, which prevents the managed object from being collected. A call to the EnumWindows method passes a delegate and a managed object (both declared as managed types, but not shown), and casts the handle to an IntPtr. The unmanaged function passes the type back to the caller as a parameter of the callback function.

using System;
using System.IO;
using System.Threading;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Security.Permissions;

public delegate bool CallBack(int handle, IntPtr param);

public class LibWrap
	// passing managed object as LPARAM
	// BOOL EnumWindows(WNDENUMPROC lpEnumFunc, LPARAM lParam);

	public static extern bool EnumWindows(CallBack cb, IntPtr param);

public class App
	public static void Main()

        [SecurityPermission(SecurityAction.Demand, UnmanagedCode=true)]
	public static void Run()
		TextWriter tw = System.Console.Out;
		GCHandle gch = GCHandle.Alloc(tw);

		CallBack cewp = new CallBack(CaptureEnumWindowsProc);

		// platform invoke will prevent delegate to be garbage collected
		// before call ends

		LibWrap.EnumWindows(cewp, GCHandle.ToIntPtr(gch));

	private static bool CaptureEnumWindowsProc(int handle, IntPtr param)
		GCHandle gch = GCHandle.FromIntPtr(param);
		TextWriter tw = (TextWriter)gch.Target;
		return true;


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

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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