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D3DImage.IsFrontBufferAvailable Property

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.

Identifier field

IsFrontBufferAvailableProperty

Metadata properties set to true

None

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.

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

            _lastRender = args.RenderingTime;
        }
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5 SP1, 3.0 SP2

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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