为什么在切换监视器时会意外地表现出DWMGETWINDOWATTRIBUTE，而DWMWA_EXTEDDEND_FRAM

当我的Winform应用程序从主监视器移动到辅助监视器时，这些属性返回的范围(窗口的高度和宽度(值和Winapi函数不会更改：ul>

form.bounds

form.size

getWindowRect((

但是DwmGetWindowAttribute返回的DWMWA_EXTENDED_FRAME_BOUNDS返回的值急剧变化。

在注释中提出的建议之后：例如，在主监视器中 dwmgetWindowAttribute 返回宽度和高度292, 100的rect，而其他值返回306, 107。考虑到滴影占7像素，这是连贯的。但是，当窗口移动到辅助显示器时， dwmgetWindowAttribute 返回 437, 150 ，其他方法返回相同的306, 107

实际上，我的两个监视器均为决议1920 * 1080(但尺度有所不同，如果很重要(

问题：为什么这样会这样？是我还是其他人面临类似的问题？最终，我想计算落下阴影大小。还有其他方法吗？

复制：

如果您想复制此功能，请创建一个Winform项目。使用 AllocConsole((在构造函数中分配控制台。为LocationChanged添加事件处理程序，然后将以下代码添加到事件处理程序：

private void AgentMainForm_LocationChanged(object sender, EventArgs e)
{
      Console.WriteLine("bounds: {0}, {1}", Bounds.Width, Bounds.Height);
      Console.WriteLine("Size: {0}, {1}", Size.Width, Size.Height);
      Console.WriteLine("Window Rect: {0}, {1}", GetSizeWithShadow().Width, GetSizeWithShadow().Height);
      Console.WriteLine("Window Rect: {0}, {1}", GetSizeWithoutShadow().Width, GetSizeWithoutShadow().Height);
}
[DllImport("user32.dll", SetLastError = true)]
public static extern bool GetWindowRect(IntPtr hwnd, out RECT lpRect);
[DllImport("dwmapi.dll")]
public static extern int DwmGetWindowAttribute(IntPtr hwnd, int dwAttribute, out RECT pvAttribute, int cbAttribute);
public Size GetSizeWithoutShadow()
{
      RECT regionWithoutShadow;
      IntPtr hWnd = this.Handle;
      if (Environment.OSVersion.Version.Major < 6) //DwmGetWindowAttribute does not work in XP, compatible only from Vista
      {
            GetWindowRect(hWnd, out regionWithoutShadow);
      }
      else
      {
            if (DwmGetWindowAttribute(hWnd, DWMWA_EXTENDED_FRAME_BOUNDS, out regionWithoutShadow, Marshal.SizeOf(typeof(RECT))) != 0)
            {
                 //Handle for failure
            }
      }
      return new Size(regionWithoutShadow.right - regionWithoutShadow.left, regionWithoutShadow.bottom - regionWithoutShadow.top);
}
public Size GetSizeWithShadow()
{
     RECT regionWithoutShadow;
     IntPtr hWnd = this.Handle;
     GetWindowRect(hWnd, out regionWithoutShadow);
     return new Size(regionWithoutShadow.right - regionWithoutShadow.left, regionWithoutShadow.bottom - regionWithoutShadow.top);
}
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
    public int left;
    public int top;
    public int right;
    public int bottom;
}