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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

The WindowInteropHelper type exposes the following members.

Public methodWindowInteropHelperInitializes a new instance of the WindowInteropHelper class for a specified Windows Presentation Foundation (WPF) window. 

Public propertyHandleGets the window handle for a Windows Presentation Foundation (WPF) window that is used to create this WindowInteropHelper.
Public propertyOwnerGets or sets the handle of the Windows Presentation Foundation (WPF) owner window.

Public methodEnsureHandleCreates the HWND of the window if the HWND has not been created yet.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

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 box. 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 WPF Window 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.

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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