index.js:33 Uncaught TypeError: Failed to execute 'createRadialGradient' on 'CanvasRenderingContext2D': The provided double value is non-finite.
var gradient=context.createRadialGradient(15 + i*30 + 2, 15 + j*30 - 2, 13, 15 + i*30 + 2, 15 + j*30 - 2, 0); ? ? ? ?這行代碼提示有錯誤，怎么回事？
2016-11-10
前面的代碼有錯吧