That is, the finger can slide inside each piece of the pie chart, and then the area color area inside that piece of the pie chart will change. But I’m not good enough to write. Who has seen this kind of effect plug-in? Not really. I can only do my own research. (at present, save the web pages of others and find them normal.Use, is gradually removing redundant code. Website address of others
When the finger slides on both sides of the block, the redrawing is triggered. The ratio of each block is recalculated according to the sliding distance and redrawn according to the ratio.
First, you need to know what the condition of trigger repainting is.
Second you need to know what the ratio of redrawing is related to.
You know all these two points.