<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>椭圆</title> </head> <body> <canvas id="canvas" style="margin:0 auto;border:1px #ddd solid"> The current browser does not support Canvas, can replace the browser a try! </canvas> <script> window.onload = function(){ var canvas = document.getElementById(‘canvas‘); canvas.width = 1024; canvas.height = 768; if(canvas.getContext(‘2d‘)){ var context = canvas.getContext(‘2d‘); // 判断游览器是否认识ellipse if(context.ellipse){ // 绘制椭圆 context.beginPath(); context.ellipse(400,400,300,100,0,0,Math.PI*2); context.closePath(); context.stroke(); }else{ alert("no ellipse") } }else{ alert(‘当前游览器不支持Canvas，请更换游览器后再试！‘); } } </script> </body> </html>
原文：http://www.cnblogs.com/cynthia-wuqian/p/4991198.html