i, 包括了4个很好的例子： 1.具有多个坐标轴的GUI，主要学习控制哪一个坐标轴是绘图命令的对象和用编辑文本框读入输入的数。 2.列表框目录阅读器，主要学习获取路径，加载，打开文件 3.从列表框中存取工作区变量，学习把存在于基本工-i, including four good examples: 1. having a plurality of axes in GUI, the main learning control axis which is the object of drawing commands and edit text boxes read with the number entered. 2 list boxes catalog reader, key learning for path, load, open the file 3. Workspace from the list box to access variables, learn to exist in the basic engineering