捕获活动窗口（包括标题栏）的屏幕截图

Question

我正在尝试捕获具有活动光标的当前窗口的屏幕截图。但如果是应用程序窗口，结果总是缺少标题栏：

private void CaptureActiveWindow()
{
    IntPtr activeWindowHandle = GetForegroundWindow();

    // Get the client area of the foreground window
    GetClientRect(activeWindowHandle, out Rectangle rect);
    Point topLeft = new Point(rect.Left, rect.Top);

    // Convert the client area's top-left corner to screen coordinates
    ClientToScreen(activeWindowHandle, out topLeft);

    // Create a rectangle in screen coordinates that corresponds to the window's client area
    Rectangle bounds = new Rectangle(topLeft.X, topLeft.Y, rect.Width, rect.Height);

    // Capture the specified screen area
    using (Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height))
    {
        using (Graphics g = Graphics.FromImage(bitmap))
        {
            g.CopyFromScreen(bounds.Location, Point.Empty, bounds.Size);
        }
        SaveImage(bitmap);
    }
}

Answer 1

GetClientRect函数返回指定窗口的客户区域的客户坐标，根据定义，它不包括标题栏（以及边框和任何菜单）。要包含标题栏，请调用 GetWindowRect 函数。这需要对您的代码进行多次调整：

1. 声明一个 RECT 类型，并在 GetWindowRect 的声明中使用它代替

   Rectangle。 （RECT 具有“右”和“下”字段，而“矩形”具有“宽度”和“高度”字段。）

   [StructLayout(LayoutKind.Sequential)]
   public struct RECT
   {
       public int Left;
       public int Top;
       public int Right;
       public int Bottom;
   
       public Point Location => new Point(Left, Top);
       public int Width => Right - Left;
       public int Height => Bottom - Top;
       public Size Size => new Size(Width, Height);
   }
   
   [DllImport("user32.dll")]
   [return: MarshalAs(UnmanagedType.Bool)]
   public static extern bool GetWindowRect(IntPtr hWnd, out RECT rect);

2. GetWindowRect 返回屏幕坐标，因此删除 ClientToScreen 调用，只需将各种 RECT 值直接传递给 CopyFromScreen 即可：

   IntPtr activeWindowHandle = GetForegroundWindow();
   GetWindowRect(activeWindowHandle, out RECT rect);
   
   // Capture the specified screen area
   using (Bitmap bitmap = new Bitmap(rect.Width, rect.Height))
   {
       using (Graphics g = Graphics.FromImage(bitmap))
       {
           g.CopyFromScreen(rect.Location, Point.Empty, rect.Size);
       }
   
       SaveImage(bitmap);
   }

3. GetWindowRect 函数针对 DPI 进行了虚拟化。为了确保这不会导致任何问题，请将应用程序清单文件 (App.manifest) 添加到您的项目中，并选择加入

   dpiAware

    设置：

   <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware>