做QT编程的都知道有个QWT第三方的开源绘图库，这里上传的内容是部分源码和注释，学的时候没找到这方面的资源,这里将注释的内容贡献出来。-QT programming do know that there is a third-party open-source graphics library QWT, upload content here is part of the source code and comments, to learn when not to find resources