[DllImport("User32.dll", EntryPoint = "FindWindow")]        public static extern IntPtr FindWindow(String className, String captionName);        [DllImport("User32.dll", EntryPoint = "FindWindowEx")]        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);        [DllImport("User32.dll", EntryPoint = "SendMessage")]        public static extern string  SendMessage(IntPtr hWnd, int Msg, int wParm, int lParm);        [DllImport("User32.dll", EntryPoint = "GetWindowText")]        public static extern int GetWindowText(IntPtr hwnd, StringBuilder lpString, int cch);        public IntPtr getHandleParent(string classname, string captionname)        {            IntPtr handle = FindWindow(classname, captionname);            return handle;        }        public IntPtr getHandleChild(IntPtr hwndparent,  string lpszclass, string lpszwindow)        {            IntPtr handle = IntPtr.Zero;            if (hwndparent != IntPtr.Zero)            {                handle = FindWindowEx(hwndparent,handle,lpszclass, lpszwindow);            }            else            {                MessageBox.Show("没有找到子窗口");            }            return handle;        }              public string getTxt(IntPtr ChildHandle)        {            StringBuilder s = new StringBuilder(512);            if (ChildHandle != IntPtr.Zero)            {                int i = GetWindowText(ChildHandle, s, s.Capacity);            }            else            {                MessageBox.Show("子窗口中没有内容");            }            return s.ToString();                               }