一款基于iOS的图表的demo，用图表（包括折线图和饼图）的形式显示数据。-A graph based on iOS demo, use a chart (including line charts and pie charts) displayed in the data.

绘制折线图，非常简单的绘制demo，只需传入几个参数就能绘制出你想要的折线图-Draw a line chart, draw a very simple demo, you can just pass a few parameters you want to draw a line graph