当单击命令按钮时，实现窗体放大功能，放大后再单击该按钮则还原窗口。同时可使用热键Alt+L和Alt+B实现窗口放大或还原。-When you click the command button, the zoom feature to achieve form, enlarge and then click the button to restore the window. At the same time can use the hotkey Alt+ L and Alt+ B realize