IntPtr iptr = WindowOperator.WinApi.FindWindow(null, "Open Files");
StringBuilder className = new StringBuilder(256);
WindowOperator.WinApi.GetClassName(iptr, className, className.Capacity);
string clsName = className.ToString().ToLower();
StringBuilder title = new StringBuilder(256);
WindowOperator.WinApi.GetWindowText(iptr, title, title.Capacity);//得到窗口的标题
//#32770 Dialog
//查找子类控件
IntPtr childptr = new IntPtr();
childptr = WindowOperator.WinApi.FindWindowEx(iptr, childptr, null, "取消");
StringBuilder childname = new StringBuilder(256);
WindowOperator.WinApi.GetClassName(childptr, childname, childname.Capacity);
//点击取消这里有mouse_leftup和down都没用
//WindowOperator.WinApi.SendMessage(childptr, VM_CLICK, IntPtr.Zero, null);
WindowOperator.WinApi.SendMessage(childptr, VM_CLICK, 0, 0);