<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>hello</title>
</head>
<body>
<canvas width="600px" height="600px" id="mycanvas"></canvas>
<script type="text/javascript">
var canvas=document.getElementById('mycanvas');
if(canvas.getContext){
var ctx=canvas.getContext('2d');
}
////绘制线
ctx.beginPath();
ctx.moveTo(50,50);
ctx.lineTo(100,100);
ctx.lineTo(80,90);
ctx.lineWidth=2;
//线条颜色
ctx.strokeStyle='#ff0000';
ctx.stroke();
////绘制矩形（实心）
ctx.clearRect(60,50,20,20);
//清除指定矩形区域
ctx.fillRect(160,150,70,80);
ctx.strokeStyle='orange'
ctx.strokeRect(170,160,50,50);
////绘制文本
ctx.font='Bold 20px Arial';
ctx.textAlign='left';
ctx.fillStyle='brown';
ctx.fillText('hello canvas',0,200);
////绘制空心文本
ctx.strokeStyle='gray';
ctx.strokeText('hello.canvas',0,260);
////绘制圆
ctx.beginPath();
ctx.arc(80,360,40,0,Math.PI*2,true);
ctx.fillStyle='yellow';
ctx.fill();
////绘制空心圆
ctx.beginPath();
ctx.arc(180,360,40,0,Math.PI*2,true);
ctx.strokeStyle='green';
ctx.lineWidth=1.0;
ctx.stroke();
////绘制渐变色，填充矩形
var myGradient=ctx.createLinearGradient(0,700,160,160);
myGradient.addColorStop(0,'red');
myGradient.addColorStop(1,'yellow');
ctx.fillStyle=myGradient;
//绘制阴影
ctx.shadowOffsetX=2;
ctx.shadowOffsetY=2;
ctx.shadowBlur=3;
ctx.shadowColor='rgba(22,22,22,.5)';
ctx.fillRect(0,420,160,160);
</script>
</body>
</html>
