c# - 如何检查窗口是否为 MDI 窗口？

Question

我想有一些 user32.dll 调用可以用来验证窗口是否是 MDI 窗口，例如使用 DefMDIChildProc 并查看它是否失败，但我想知道这是否有任何限制，或者是否有更好的方法来做到这一点? 检查父母是否足够？

为简单起见，我最终希望的是一种 IsMDI(IntPtr ptr) 类型的调用......

想法？建议？

score 4 · Accepted Answer

我已经想通了（在 pinvoke.net 的帮助下）-您可以根据扩展的 Windows 样式找到：

        public static bool IsMDI(IntPtr hwnd)
        {
            WINDOWINFO info = new WINDOWINFO();
            info.cbSize = (uint)Marshal.SizeOf(info);
            GetWindowInfo(hwnd, ref info);
            //0x00000040L is the style for WS_EX_MDICHILD
            return (info.dwExStyle & 0x00000040L)==1;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct WINDOWINFO
        {
            public uint cbSize;
            public RECT rcWindow;
            public RECT rcClient;
            public uint dwStyle;
            public uint dwExStyle;
            public uint dwWindowStatus;
            public uint cxWindowBorders;
            public uint cyWindowBorders;
            public ushort atomWindowType;
            public ushort wCreatorVersion;

            public WINDOWINFO(Boolean? filler)
                : this()   // Allows automatic initialization of "cbSize" with "new WINDOWINFO(null/true/false)".
            {
                cbSize = (UInt32)(Marshal.SizeOf(typeof(WINDOWINFO)));
            }

        }

        [return: MarshalAs(UnmanagedType.Bool)]
        [DllImport("user32.dll", SetLastError = true)]
        private static extern bool GetWindowInfo(IntPtr hwnd, ref WINDOWINFO pwi);