为什么在切换监视器时 DwmGetWindowAttribute 和 DWMWA_EXTENDED_FRAME_BOUNDS 的行为异常?

本文介绍了为什么在切换监视器时 DwmGetWindowAttribute 和 DWMWA_EXTENDED_FRAME_BOUNDS 的行为异常?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

当我的 WinForm 应用程序从主监视器移动到辅助监视器时，这些属性和 winapi 函数返回的边界(窗口的高度和宽度)值不会改变:

When my WinForm application is moved from a primary monitor to a secondary monitor, the bounds (Height and Width of the Window) value returned by these properties and winapi function does not change :

Form.Bounds
形式.大小
GetWindowRect()

但是 DwmGetWindowAttribute 和 DWMWA_EXTENDED_FRAME_BOUNDS 返回的值发生了巨大的变化.

But the value returned by DwmGetWindowAttribute with DWMWA_EXTENDED_FRAME_BOUNDS changes drastically.

根据评论的建议进行例如，在主监视器中 DwmgetWindowAttribute 返回宽度和高度 292, 100 和其他值返回 306, 107.考虑到投影占用 7 个像素，这是连贯的.但是当窗口移动到辅助监视器时，DwmgetWindowAttribute返回437, 150，其他方法返回相同的306, 107

Edits after suggestion from comments: For instance, in the primary monitor DwmgetWindowAttribute returns a rect of width and height 292, 100 and the other values return 306, 107. This is coherent considering the drop shadow takes up 7 pixels. But when the window is moved to the secondary monitor, DwmgetWindowAttribute returns 437, 150 and the other methods return the same 306, 107

事实上，我的两台显示器的分辨率都是 1920 * 1080(但如果重要的话，比例会有所不同)

In fact both my monitors are of resolution 1920 * 1080 (but the scale differs though if it matters)

问题:为什么会这样?是只有我还是其他人遇到过类似的问题?最终我想计算阴影大小.还有其他办法吗?

Question: Why does this happen this way? Is it only me or have anyone else faced similar issues? Ultimately I want to calculate the drop shadow size. Is there any other way?

复制:

如果您希望重现此内容，请创建一个 winform 项目.在构造函数中使用 AllocConsole() 分配控制台.为 LocationChanged 添加一个事件处理程序，并将以下代码添加到事件处理程序中:

If you wish to reproduce this, create a winform project. Allocate console using AllocConsole() in the constructor. Add an event handler for LocationChanged and add the following code to the event handler:

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;
}

为什么在切换监视器时

为什么在切换监视器时 DwmGetWindowAttribute 和 DWMWA_EXTENDED_FRAME_BOUNDS 的行为异常?

问题描述

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