窗口使用缺省的布局方式，窗口中有自定义的画布（中间）和控制画布的面板（南面），点击面板中的按钮“画图”和“图片”，分别在画布中实现对应的功能-Window uses the default layout, custom canvas (middle), and control of the canvas panels (south) in the window, click the button in the panel " Paint"　and " Pictures" , respectively, in the corresponding function in the canvas