说明：  这是一个很有用的代码，可以用于任何画波形的背景设置，网格和坐标设置。只要直接将两个文件加入到工程文件和工程下就可以直接使用。
(This is a very useful code, the waveform can be used to set the background of any picture, set the grid and coordinates. As long as the two files directly into the project file and can be used directly under the project.)