一个类似Windows画图板的小程序，拿来和大家分享一下。功能主要有： 手绘线、简单图形、文字输入、图块拖放、重复撤销、画面缩放、打开保存图片文件.-A similar drawing board of a small Windows program, use and share with you. The main features include: hand-drawn lines, simple graphics, text input, drag and drop block, repe