D3DImage.IsFrontBufferAvailable Property


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Gets a value that indicates whether a front buffer exists.

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

public bool IsFrontBufferAvailable { get; }

Property Value

Type: System.Boolean

true if a front buffer exists; otherwise, false.

Occasionally, the front buffer becomes unavailable. This lack of availability can be caused by screen locking, full-screen exclusive Direct3D applications, user-switching, or other system activities. When this occurs, your WPF application is notified by handling the IsFrontBufferAvailableChanged event. How your application responds to the front buffer becoming unavailable depends on whether WPF is enabled to fall back to software rendering. The SetBackBuffer method has an overload that takes a parameter that specifies whether WPF falls back to software rendering. For more information, see the remarks in the D3DImage class.

Identifier field


Metadata properties set to true


The following code example shows how to check the IsFrontBufferAvailable property when rendering the composition target. For more information, see Walkthrough: Hosting Direct3D9 Content in WPF.

void CompositionTarget_Rendering(object sender, EventArgs e)
    RenderingEventArgs args = (RenderingEventArgs)e;

    // It's possible for Rendering to call back twice in the same frame 
    // so only render when we haven't already rendered in this frame.
    if (d3dimg.IsFrontBufferAvailable && _lastRender != args.RenderingTime)
        IntPtr pSurface = IntPtr.Zero;
        HRESULT.Check(GetBackBufferNoRef(out pSurface));
        if (pSurface != IntPtr.Zero)
            // 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));

            _lastRender = args.RenderingTime;

.NET Framework
Available since 3.0
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