列如这个样子,可以画出来吗
What ashuang520 is asking:
"Is it possible to add shades (The purple area) between 2 lines?"
My problem is this ,Can you do it?(对,就是两条曲线 之间加阴影,可以实现吗?谢谢)
My suggestion is:

There will be a problem with a negative filling,This blank area is not drawn,It belongs to the white shadow drawn by second lines,Is there a way to solve it? thank you(存在负数填充就会出现这个问题,这个空白区域绘制不出来,它属于第二条线 绘制出来的白色阴影,有办法解决吗?谢谢)
I tried your suggestion, but encountered a problem. When I set the fillalpha for lower dataSet to 255, the borders of the chart were occluded.How can I avoid this problem
Most helpful comment
My suggestion is:
Try that approach and say if it works.