读取数据流 sharpDX 错误所有值均为 0

Question

我在我的项目中遵循了这个解决方案：How to create bitmap from Surface (SharpDX)

我没有足够的声誉来发表评论，所以我在这里提出一个新问题。

我的项目基本上是Direct 2D，我有一个Surface buffer，一个swapchain。我想将我的缓冲区放入数据流中并读取它的值以将其放入位图中并将其保存在磁盘上（如屏幕截图），但我的代码将无法工作，因为所有字节值为 0（黑色）这没有意义，因为我的图像是全白的，带有一点蓝色。

这是我的代码：

SwapChainDescription description = new SwapChainDescription()
     {
        ModeDescription = new ModeDescription(this.Width, this.Height, new Rational(60, 1), Format.B8G8R8A8_UNorm),
        SampleDescription = new SampleDescription(1, 0),
        Usage = Usage.RenderTargetOutput,
        BufferCount = 1,
        SwapEffect = SwapEffect.Discard,
        IsWindowed = true,
        OutputHandle = this.Handle
     };

     Device.CreateWithSwapChain(DriverType.Hardware, DeviceCreationFlags.Debug | DeviceCreationFlags.BgraSupport, description, out device, out swapChain);

     SharpDX.DXGI.Device dxgiDevice = device.QueryInterface<SharpDX.DXGI.Device>();
     SharpDX.DXGI.Adapter dxgiAdapter = dxgiDevice.Adapter;

     SharpDX.Direct2D1.Device d2dDevice = new SharpDX.Direct2D1.Device(dxgiDevice);
     d2dContext = new SharpDX.Direct2D1.DeviceContext(d2dDevice, SharpDX.Direct2D1.DeviceContextOptions.None);
     SharpDX.Direct3D11.DeviceContext d3DeviceContext = new SharpDX.Direct3D11.DeviceContext(device);




     properties = new BitmapProperties(new SharpDX.Direct2D1.PixelFormat(SharpDX.DXGI.Format.B8G8R8A8_UNorm, SharpDX.Direct2D1.AlphaMode.Premultiplied),
          96, 96);

     Surface backBuffer = swapChain.GetBackBuffer<Surface>(0);
     d2dTarget = new SharpDX.Direct2D1.Bitmap(d2dContext, backBuffer, properties);

     d2dContext.Target = d2dTarget;

     playerBitmap = this.LoadBitmapFromContentFile(@"C:\Users\ndesjardins\Desktop\wave.png");

     //System.Drawing.Bitmap bitmapCanva = new System.Drawing.Bitmap(1254, 735);

     d2dContext.BeginDraw();
     d2dContext.Clear(SharpDX.Color.White);
     d2dContext.DrawBitmap(playerBitmap, new SharpDX.RectangleF(0, 0, playerBitmap.Size.Width, playerBitmap.Size.Height), 1f, SharpDX.Direct2D1.BitmapInterpolationMode.NearestNeighbor);
     SharpDX.Direct2D1.SolidColorBrush brush = new SharpDX.Direct2D1.SolidColorBrush(d2dContext, SharpDX.Color.Green);
     d2dContext.DrawRectangle(new SharpDX.RectangleF(200, 200, 100, 100), brush);
     d2dContext.EndDraw();

     swapChain.Present(1, PresentFlags.None);


     Texture2D backBuffer3D = backBuffer.QueryInterface<SharpDX.Direct3D11.Texture2D>();

     Texture2DDescription desc = backBuffer3D.Description;
     desc.CpuAccessFlags = CpuAccessFlags.Read;
     desc.Usage = ResourceUsage.Staging;
     desc.OptionFlags = ResourceOptionFlags.None;
     desc.BindFlags = BindFlags.None;

     var texture = new Texture2D(device, desc);

     d3DeviceContext.CopyResource(backBuffer3D, texture);

     byte[] data = null;
     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];

        dataStream.Position = 0;
        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();

        int width = surface.Description.Width;
        int height = surface.Description.Height;
        byte[] bytewidth = BitConverter.GetBytes(width);
        byte[] byteheight = BitConverter.GetBytes(height);

        Array.Copy(bytewidth, 0, data, 0, 4);
        Array.Copy(byteheight, 0, data, 4, 4);

     }

你们知道为什么最后返回的字节数组全是 0，因为它应该大部分是 255 吗？我在后台缓冲区中所做的只是绘制位图图像和矩形形式。 Array.Copy 是将宽度和高度 header 添加到字节数组，因此我可以从中创建位图。

Answer 1

我在评论中回答了，但格式很糟糕，所以很抱歉！

https://gamedev.stackexchange.com/a/112978/29920 这看起来很有希望，但正如你在回复我时所说的那样，这是一段时间以前的事了，我正在凭空提出，如果它不起作用或者有更多当前知识的人必须回答，否则我将不得不获取一些源代码并自己尝试。

SharpDX.Direct2D1.Bitmap dxbmp = new SharpDX.Direct2D1.Bitmap(renderTarget, 
new SharpDX.Size2(bmpWidth, bmpHeight), new 
BitmapProperties(renderTarget.PixelFormat));
dxbmp.CopyFromMemory(bmpBits, bmpWidth * 4);

这看起来有点像您需要的。我假设这里的 bmpBits 是字节数组或内存流，然后可以将其中任何一个保存下来，或者至少给你一些东西看看你是否真的在获取像素数据

读取数据流 sharpDX 错误所有值均为 0

Reading Datastream sharpDX Error all values are 0

c#

sharpdx