//建立顶级窗口 toplevel = XtVaAppInitialize[&app, "DrawArea", NULL, 0, &argc, argv, NULL, NULL]
//建立顶级窗口 toplevel = XtVaAppInitialize[&app, "DrawArea", NULL, 0, &argc, argv, NULL, NULL] ...
//建立顶级窗口 toplevel = XtVaAppInitialize[&app, "DrawArea", NULL, 0, &argc, argv, NULL, NULL] ...