dxgi返回黑色位图，桌面区域捕获

Question

当使用涡流捕获桌面时，它可以正常工作。虽然，当我尝试使用矩形的x或y位置以外的任何其他值时，它仅作为黑色位图返回框架。我用于参考的代码位于此处： https：// github。 com/diogotr7/desktopduplicationsamples/blob/master/vorticecore/program.cs ，但它遇到了相同的问题。我尝试更改var框架中的大多数值，而var mapdest却没有很多运气。

public void Start()
{
    _isCapturing = true;
    DXGI.CreateDXGIFactory1<IDXGIFactory1>(out var factory);
    if (factory == null)
    {
        return;
    }
    var adapter = factory.GetAdapter(0);
    var output = adapter.GetOutput(0);
    var output1 = output.QueryInterface<IDXGIOutput1>();
    //D3D12.D3D12CreateDevice(adapter, FeatureLevel.Level_12_0, out ID3D12Device? device);
    D3D11.D3D11CreateDevice(adapter, DriverType.Unknown, DeviceCreationFlags.None, _featureLevels, out var device);
    if (device == null)
        throw new Exception("Unable to Locate Device.");

    // Width/Height of desktop to capture
    Rectangle rectangle = new Rectangle(0, 0,
            output.Description.DesktopCoordinates.Right,
            output.Description.DesktopCoordinates.Bottom);

    // Create Staging texture CPU-accessible
    var texture2dDescription = new Texture2DDescription
    {
        ArraySize = 1,
        BindFlags = BindFlags.None,
        CPUAccessFlags = CpuAccessFlags.Read | CpuAccessFlags.Write,
        Format = Format.B8G8R8A8_UNorm,
        Height = rectangle.Bottom,
        MipLevels = 1,
        SampleDescription = { Count = 1, Quality = 0 },
        Usage = ResourceUsage.Staging,
        Width = rectangle.Right
    };
    
    Task.Factory.StartNew(() =>
    {
        // Duplicate the output
        using var duplicatedOutput = output1.DuplicateOutput(device);
        while (_isCapturing)
        {
            try
            {
                var currentFrame = device.CreateTexture2D(texture2dDescription);

                Thread.Sleep(50);
                rectangle.X = 0;
                duplicatedOutput.AcquireNextFrame(100, out var frameInfo, out var desktopResource);
                if (desktopResource == null)
                    continue;
                var tempTexture = desktopResource.QueryInterface<ID3D11Texture2D>();
                device.ImmediateContext.CopyResource(currentFrame, tempTexture);
                var dataBox = device.ImmediateContext.Map(currentFrame, 0);
                var frame = new Bitmap(rectangle.Right, rectangle.Bottom, PixelFormat.Format32bppRgb);
                var mapDest = frame.LockBits(rectangle, ImageLockMode.WriteOnly, frame.PixelFormat);
                for (int y = rectangle.Y, sizeInBytesToCopy = rectangle.Width * 4; y < rectangle.Height; y++)
                {
                    MemoryHelpers.CopyMemory(mapDest.Scan0 + y * rectangle.Right * 4,
                        dataBox.DataPointer + y * dataBox.RowPitch, sizeInBytesToCopy);
                }

                frame.UnlockBits(mapDest);
                ScreenRefreshed?.Invoke(this, frame);
                desktopResource.Dispose();
                frame.Dispose();
                tempTexture.Dispose();
                currentFrame.Dispose();
            }
            catch (Exception e)
            {
                if (e.HResult != Vortice.DXGI.ResultCode.WaitTimeout.Code)
                {
                    Trace.TraceError(e.Message);
                    Trace.TraceError(e.StackTrace);
                }
            }

            duplicatedOutput.ReleaseFrame();
        }
    });
}

Answer 1

您的代码存在问题。以下是说明为什么它不超过一次的问题，需要一个奇怪的睡眠呼叫：

• 您不处理所有内容（您应该，我想这是在释放基础com接口）
• 。 't
• 您不会获得的帧。

但是，还有其他问题

• 可以使用D3D11 CreatedEvice创建的设备上下文，您无需使用此即时Ectext属性。
• 如果您想最大程度地提高重复性能，则不应直接在获取帧循环中使用CPU映射的纹理，您必须保持非常快。您应该将它们复制（就像您一样），然后使用另一个线程将它们传递到CPU，例如
• 重复API是 屏幕捕获API，它是屏幕重复API（！），这意味着它将将渲染框架复制到喜欢的“邮箱”，您可以在可能的情况下查询。超时可以保持相对重要。当您暂停时，这只是意味着屏幕上没有任何更改。 frameinfo参数具有有关所有这些的有用信息。

这是一个似乎可以使用的版本（获取10帧并将其保存为位图文件）：

class Program
{
    private static readonly FeatureLevel[] _featureLevels = new[]
    {
        FeatureLevel.Level_11_0,
        FeatureLevel.Level_10_1,
        FeatureLevel.Level_10_0,
        FeatureLevel.Level_9_3,
        FeatureLevel.Level_9_2,
        FeatureLevel.Level_9_1,
    };

    static void Main()
    {
        DXGI.CreateDXGIFactory1<IDXGIFactory1>(out var factory);
        if (factory == null)
            return;

        using (factory)
        {
            using var adapter = factory.GetAdapter(0);
            using var output = adapter.GetOutput(0);
            using var output1 = output.QueryInterface<IDXGIOutput1>();
            D3D11.D3D11CreateDevice(adapter, DriverType.Unknown, DeviceCreationFlags.None, _featureLevels, out var device, out var deviceContext);
            if (device == null)
                return;

            using (device)
            {
                var rectangle = new Rectangle(0, 0, output.Description.DesktopCoordinates.Right, output.Description.DesktopCoordinates.Bottom);
                var texture2dDescription = new Texture2DDescription
                {
                    ArraySize = 1,
                    CPUAccessFlags = CpuAccessFlags.Read | CpuAccessFlags.Write,
                    Format = Format.B8G8R8A8_UNorm,
                    MipLevels = 1,
                    SampleDescription = { Count = 1, Quality = 0 },
                    Usage = ResourceUsage.Staging,
                    Height = rectangle.Bottom,
                    Width = rectangle.Right
                };

                using var currentFrame = device.CreateTexture2D(texture2dDescription);
                using var duplicatedOutput = output1.DuplicateOutput(device);
                using var frame = new Bitmap(rectangle.Right, rectangle.Bottom, PixelFormat.Format32bppRgb);
                var index = 0;
                rectangle.X = 0;
                do
                {
                    duplicatedOutput.AcquireNextFrame(500, out var frameInfo, out var desktopResource);
                    if (desktopResource != null)
                    {
                        using (desktopResource)
                        {
                            using var tempTexture = desktopResource.QueryInterface<ID3D11Texture2D>();
                            deviceContext.CopyResource(currentFrame, tempTexture);
                            var dataBox = deviceContext.Map(currentFrame, 0, MapMode.Read);
                            var mapDest = frame.LockBits(rectangle, ImageLockMode.WriteOnly, frame.PixelFormat);
                            for (int y = rectangle.Y, sizeInBytesToCopy = rectangle.Width * 4; y < rectangle.Height; y++)
                            {
                                MemoryHelpers.CopyMemory(mapDest.Scan0 + y * rectangle.Right * 4, dataBox.DataPointer + y * dataBox.RowPitch, sizeInBytesToCopy);
                            }
                            deviceContext.Unmap(currentFrame, 0);
                            frame.UnlockBits(mapDest);
                            frame.Save("bitmap" + index++ + ".png", ImageFormat.Png);
                        }
                    }

                    duplicatedOutput.ReleaseFrame();
                }
                while (index < 10);
            }
        }
    }
}