directx-11 - 如何从 Surface (SharpDX) 创建位图

Question

我是 DirectX 的新手，并尝试使用 SharpDX 使用桌面复制 API 捕获屏幕截图。

我想知道是否有任何简单的方法可以创建可以在 CPU 中使用的位图(即保存在文件中等)

我正在使用以下代码获取桌面屏幕截图:

var factory = new SharpDX.DXGI.Factory1();
var adapter = factory.Adapters1[0];
var output = adapter.Outputs[0];

var device = new SharpDX.Direct3D11.Device(SharpDX.Direct3D.DriverType.Hardware,
                                                       DeviceCreationFlags.BgraSupport |
                                                       DeviceCreationFlags.Debug);

var dev1 = device.QueryInterface<SharpDX.DXGI.Device1>();

var output1 = output.QueryInterface<Output1>();
var duplication = output1.DuplicateOutput(dev1);
OutputDuplicateFrameInformation frameInfo;
SharpDX.DXGI.Resource desktopResource;
duplication.AcquireNextFrame(50, out frameInfo, out desktopResource);

var desktopSurface = desktopResource.QueryInterface<Surface>();

谁能给我一些关于如何从 desktopSurface(DXGI.Surface 实例)创建位图对象的想法？

Answer 1

我自己刚刚完成了这个，虽然我不会对这段代码多说!

public byte[] GetScreenData()
    {
        // We want to copy the texture from the back buffer so 
        // we don't hog it.
        Texture2DDescription desc = BackBuffer.Description;
        desc.CpuAccessFlags = CpuAccessFlags.Read;
        desc.Usage = ResourceUsage.Staging;
        desc.OptionFlags = ResourceOptionFlags.None;
        desc.BindFlags = BindFlags.None;

        byte[] data = null;

        using (var texture = new Texture2D(DeviceDirect3D, desc))
        {
            DeviceContextDirect3D.CopyResource(BackBuffer, texture);

            using (Surface surface = texture.QueryInterface<Surface>())
            {
                DataStream dataStream;
                var map = surface.Map(SharpDX.DXGI.MapFlags.Read, out dataStream);
                int lines = (int)(dataStream.Length / map.Pitch);
                data = new byte[surface.Description.Width * surface.Description.Height * 4];

                int dataCounter = 0;
                // width of the surface - 4 bytes per pixel.
                int actualWidth = surface.Description.Width * 4;
                for (int y = 0; y < lines; y++)
                {
                    for (int x = 0; x < map.Pitch; x++)
                    {
                        if (x < actualWidth)
                        {
                            data[dataCounter++] = dataStream.Read<byte>();
                        }
                        else
                        {
                            dataStream.Read<byte>();
                        }
                    }
                }
                dataStream.Dispose();
                surface.Unmap();
            }
        }

        return data;
    }

这将为您提供一个 byte[]，然后可以使用它来生成位图。

以下是我如何保存到 png 图像。

 using (var stream = await file.OpenAsync( Windows.Storage.FileAccessMode.ReadWrite ))
            {
                BitmapEncoder encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
                double dpi = DisplayProperties.LogicalDpi;

                encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight,
                    (uint)width, (uint)height, dpi, dpi, pixelData);
                encoder.BitmapTransform.ScaledWidth = (uint)newWidth;
                encoder.BitmapTransform.ScaledHeight = (uint)newHeight;
                await encoder.FlushAsync();
                waiter.Set();
            }

我知道这是不久前回答的，也许你现在已经明白了:3 但如果其他人被卡住了，我希望这会有所帮助!