WindowInteropHelper Class

Assists interoperation between Windows Presentation Foundation (WPF) and Win32 code.

Namespace: System.Windows.Interop
Assembly: PresentationFramework (in presentationframework.dll)

public sealed class WindowInteropHelper
public final class WindowInteropHelper
public final class WindowInteropHelper
You cannot use this managed class in XAML.

Members of this class allows the caller to have internal access to the Win32 HWND and the parent HWND of a WPF Window.  The proper security checks are performed by those members.

Use this class whenever you need a more specific object based on its HWND.

An example scenario is if you need to host a WPF dialog box in a Win32 application. Initialize the WindowInteropHelper with a WPF window object for the dialog. You can then get the WPF window's handle (HWND) from the Handle property and specify the owner for the WPF window with the Owner property. The following code example shows how to use WindowInteropHelper when hosting a WPF dialog box in a Win32 application.

WindowInteropHelper wih = new WindowInteropHelper(myDialog);
wih.Owner = ownerHwnd;

Another scenario supported by this class is to obtain a HwndSource object from a WPFWindow object. The HwndSource enables direct processing of Win32 messages through the AddHook method. By using HwndSource and AddHook in place of a Window you can still handle messages that have no equivalent or handling in WPF. Create a WindowInteropHelper with the Window source , then call Handle on the WindowInteropHelper to get from HWND to HwndSource.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0