是否可以修复黑色截图？ [英] Is it possible to fix black screenshots?

问题描述

您好，我目前正在尝试通过BitBlt激活抗锯齿模式捕获全屏游戏，但它会返回黑色屏幕截图。如果我禁用抗锯齿，截图效果很好。



有什么想法吗？



这是代码我使用：

 public Image CaptureWindow（IntPtr句柄）
 {
 //获取目标的DC window 
 IntPtr hdcSrc = User32.GetWindowDC（handle）; 
 
 //获取大小
 User32.RECT windowRect = new User32.RECT（）; 
 User32.GetWindowRect（handle，ref windowRect）; 
 int width = windowRect.right  -  windowRect.left; 
 int height = windowRect.bottom  -  windowRect.top; 
 
 //创建我们可以复制到
的设备上下文IntPtr hdcDest = GDI32.CreateCompatibleDC（hdcSrc）; 
 
 //创建一个我们可以复制到的位图，
 //使用GetDeviceCaps获取宽度/高度
 IntPtr hBitmap = GDI32.CreateCompatibleBitmap（hdcSrc，width，height） ; 
 
 //选择位图对象
 IntPtr hOld = GDI32.SelectObject（hdcDest，hBitmap）; 
 
 // bitblt over 
 GDI32.BitBlt（hdcDest，0,0，width，height，hdcSrc，0,0，CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt）; 
 
 //恢复选择
 GDI32.SelectObject（hdcDest，hOld）; 
 
 //清理
 GDI32.DeleteDC（hdcDest）; 
 User32.ReleaseDC（handle，hdcSrc）; 
 
 //为它获取一个.NET图像对象
 Image img = Image.FromHbitmap（hBitmap）; 
 
 //释放Bitmap对象
 GDI32.DeleteObject（hBitmap）; 
 
返回img; 
} 

  private   class  GDI32 
 {
 
  //   public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop参数 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   bool  BitBlt（ IntPtr  hObject， int  nXDest， int  nYDest，
  int  nWidth， int  nHeight， IntPtr  hObjectSource，
  int  nXSrc， int  nYSrc，CopyPixelOperation rop）; 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   IntPtr  CreateCompatibleBitmap（ IntPtr  hDC， int  nWidth，
  int  nHeight）; 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   IntPtr  CreateCompatibleDC（ IntPtr  hDC）; 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   bool  DeleteDC（ IntPtr  hDC）; 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   bool  DeleteObject（ IntPtr  hObject）; 
 
 [DllImport（  gdi32.dll）] 
  public   static   extern   IntPtr  SelectObject（ IntPtr  hDC， IntPtr  hObject）; 
} 
 
  ///    <  摘要 >  
   ///  包含User32 API函数的助手类
   ///   <   / summary  >  
  
  private   class  User32 
 {
 [StructLayout（LayoutKind.Sequential）] 
  public   struct  RECT 
 {
  public   int  left; 
  public   int  top; 
  public   int  right; 
  public   int  bottom; 
} 
 
 [DllImport（  user32.dll） ] 
  public   static   extern   IntPtr  GetDesktopWindow（）; 
 
 [DllImport（  user32.dll）] 
  public   static   extern   IntPtr  GetWindowDC（ IntPtr  hWnd）; 
 
 [DllImport（  user32.dll）] 
  public   static   extern   IntPtr  ReleaseDC（ IntPtr  hWnd， IntPtr  hDC）; 
 
 [DllImport（  user32.dll）] 
  public   static   extern   IntPtr  GetWindowRect（ IntPtr  hWnd， ref  RECT rect）; 
} 
} 
} 

解决方案

绝对不需要使用P / Invoke您的Forms应用程序。您需要的所有GDI +都可以在 System.Drawing 中找到：

http://msdn.microsoft.com/en-us/library/system.drawing.aspx [ ^ ]。



< DD> -SA

Hello, I'm currently trying to capture a fullscreen game with antialiasing mode activated via BitBlt, but it returns a black screenshot. If I disable the antialiasing, the screenshot works perfectly.

Any ideas?

Here's the code I'm using:

public Image CaptureWindow(IntPtr handle)
        {
            // get the DC of the target window
            IntPtr hdcSrc = User32.GetWindowDC(handle);

            // get the size
            User32.RECT windowRect = new User32.RECT();
            User32.GetWindowRect(handle, ref windowRect);
            int width = windowRect.right - windowRect.left;
            int height = windowRect.bottom - windowRect.top;

            // create a device context we can copy to
            IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);

            // create a bitmap we can copy it to,
            // using GetDeviceCaps to get the width/height
            IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, width, height);

            // select the bitmap object
            IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);

            // bitblt over
            GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt);

            // restore selection
            GDI32.SelectObject(hdcDest, hOld);

            // clean up 
            GDI32.DeleteDC(hdcDest);
            User32.ReleaseDC(handle, hdcSrc);

            // get a .NET image object for it
            Image img = Image.FromHbitmap(hBitmap);

            // free up the Bitmap object
            GDI32.DeleteObject(hBitmap);

            return img;
        }

private class GDI32
        {

            //public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter

            [DllImport("gdi32.dll")]
            public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest,
                int nWidth, int nHeight, IntPtr hObjectSource,
                int nXSrc, int nYSrc, CopyPixelOperation rop);

            [DllImport("gdi32.dll")]
            public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth,
                int nHeight);

            [DllImport("gdi32.dll")]
            public static extern IntPtr CreateCompatibleDC(IntPtr hDC);

            [DllImport("gdi32.dll")]
            public static extern bool DeleteDC(IntPtr hDC);

            [DllImport("gdi32.dll")]
            public static extern bool DeleteObject(IntPtr hObject);

            [DllImport("gdi32.dll")]
            public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
        }

        /// <summary>
        /// Helper class containing User32 API functions
        /// </summary>

        private class User32
        {
            [StructLayout(LayoutKind.Sequential)]
            public struct RECT
            {
                public int left;
                public int top;
                public int right;
                public int bottom;
            }

            [DllImport("user32.dll")]
            public static extern IntPtr GetDesktopWindow();

            [DllImport("user32.dll")]
            public static extern IntPtr GetWindowDC(IntPtr hWnd);

            [DllImport("user32.dll")]
            public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);

            [DllImport("user32.dll")]
            public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
        }
    }
}

解决方案

There is absolutely no need to use P/Invoke with your Forms application. All you need from GDI+ is available in System.Drawing:
http://msdn.microsoft.com/en-us/library/system.drawing.aspx[^].

—SA

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