基于单文档视图结架，添加工具栏的示例，对初学者起个启示作用-based on single-file View Guitar, add toolbars example, the right to take a beginners inspiration

单文档 多界面 分割视图 通过工具栏的新增的下拉菜单来切换各个界面 并同时动态更换菜单的程序-Single document multiple split screen views through the new toolbar drop-down menu to switch dynamically changing all the menu interface and the program also