c# - 如何获取WinForm应用程序中最顶层表单的句柄？

我有一个具有其他子窗体(不是mdi)的WinForm应用程序。如果用户按下“Esc”，则即使没有焦点，最上面的窗体也应关闭。

我可以使用键盘 Hook 全局捕获Escape，但还需要关闭表单的句柄。

我猜有一种使用Win32 API的方法，但是有使用托管代码的解决方案吗？

最佳答案

这是获取使用Win32的最高级表单的一种方法(虽然不是很优雅，但是可以工作):

public const int GW_HWNDNEXT = 2; // The next window is below the specified window
public const int GW_HWNDPREV = 3; // The previous window is above

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

[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool IsWindowVisible(IntPtr hWnd);

[DllImport("user32.dll", CharSet = CharSet.Auto, EntryPoint = "GetWindow", SetLastError = true)]
public static extern IntPtr GetNextWindow(IntPtr hwnd, [MarshalAs(UnmanagedType.U4)] int wFlag);

/// <summary>
/// Searches for the topmost visible form of your app in all the forms opened in the current Windows session.
/// </summary>
/// <param name="hWnd_mainFrm">Handle of the main form</param>
/// <returns>The Form that is currently TopMost, or null</returns>
public static Form GetTopMostWindow(IntPtr hWnd_mainFrm)
{
    Form frm = null;

    IntPtr hwnd = GetTopWindow((IntPtr)null);
    if (hwnd != IntPtr.Zero)
    {
        while ((!IsWindowVisible(hwnd) || frm == null) && hwnd != hWnd_mainFrm)
        {
            // Get next window under the current handler
            hwnd = GetNextWindow(hwnd, GW_HWNDNEXT);

            try
            {
                frm = (Form)Form.FromHandle(hwnd);
            }
            catch
            {
                // Weird behaviour: In some cases, trying to cast to a Form a handle of an object
                // that isn't a form will just return null. In other cases, will throw an exception.
            }
        }
    }

    return frm;
}