How to draw a circle sector on an html5 canvas?

问题

I'm trying to make a sort of pie-chart shape on a canvas element, however I can't seem to find any function that does this by itself. I only seem to be able to draw full circles and segments. Is there an easy way to do this?

(See also: Wikipedia on circle terminology)

回答1:

The following should work:

context.moveTo(cx,cy);
context.arc(cx,cy,radius,startangle,endangle);
context.lineTo(cx,cy);
context.stroke(); // or context.fill()

with cx, cy being the center of the arc.

来源：https://stackoverflow.com/questions/6230363/how-to-draw-a-circle-sector-on-an-html5-canvas