This documentation is archived and is not being maintained.

D3DImage.Unlock Method

Updated: July 2008

Decrements the lock count for the D3DImage.

Namespace:  System.Windows.Interop
Assembly:  PresentationCore (in PresentationCore.dll)

public void Unlock()
You cannot use methods in XAML.

When the lock count for the D3DImage reaches zero, the D3DImage is fully unlocked. The D3DImage is marked for rendering if the image has changed areas that were specified by previous calls to the AddDirtyRect method.

When the changes are committed and rendering occurs, additional calls to the Lock method block until the render thread has copied the contents of the back buffer to the front buffer. This synchronization avoids display artifacts, such as tearing.


Do not update the Direct3D surface while the D3DImage is unlocked.

The following code example shows how to call the Unlock method to copy the updated back buffer to the front buffer. For more information, see Walkthrough: Hosting Direct3D9 Content in WPF.

// Repeatedly calling SetBackBuffer with the same IntPtr is  
// a no-op. There is no performance penalty.
d3dimg.SetBackBuffer(D3DResourceType.IDirect3DSurface9, pSurface);
d3dimg.AddDirtyRect(new Int32Rect(0, 0, d3dimg.PixelWidth, d3dimg.PixelHeight));

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

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

.NET Framework

Supported in: 3.5 SP1, 3.0 SP2




July 2008

Added topic for new class.

SP1 feature change.