[code]
/**
* ...画圆,半圆,弧形
* @author amyflash.com
*/
(function() {
var can = document.getElementById("canvas");
var ctx = can.getContext("2d");
ctx.font="20px Arial";
ctx.fillText("画圆,半圆,弧形",20,20);
ctx.strokeStyle="#000000";
ctx.fillStyle="rgba(255,255,0,0.5)";//"#FF0000";
ctx.lineWidth = "5";
//ctx.fillRect(50,50,200,200);
//ctx.strokeRect(50,50,200,200);
ctx.beginPath();
//ctx.arc(200,200,50,0,Math.PI*2);// 画正圆
//ctx.arc(200,200,50,0,Math.PI);// 画半圆
//画圆弧
ctx.moveTo(0,300);//起点
//ctx.quadraticCurveTo(0,0,300,0);//1个控制点和终点
ctx.bezierCurveTo(0,0,300,0,400,500,25,50);//多个控制点
ctx.fill();
ctx.stroke();
})();
[/code]