                        课程
                    
                        /前端开发
                        
                            /Html5
                        
                        /炫丽的倒计时效果Canvas绘图与动画基础

为什么我用360浏览器和火狐浏览器打开都只显示最开始的那个方框？

为什么我用火狐浏览器和360浏览器打开都只能显示一个方框？是不是要装插件？

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<canvas id="canvas" style="border:1px solid #aaa;display:block;margin:50px auto;">
当浏览器不支持Canvas，请更换浏览器后再试
</canvas>
<script type="text/javascript">
var tangram=[
{p:[{x:0,y:0},{x:800,y:0},{x:400,y:400}],color:"#caff67"},
{p:[{x:0,y:0},{x:400,y:400},{x:0,y:800}],color:"#67beef"},
{p:[{x:800,y:0},{x:800,y:400},{x:600,y:600},{x:600,y:200}],color:"#ef3d61"},
{p:[{x:600,y:200},{x:600,y:600},{x:400,y:400}],color:"#f9f5la"},
{p:[{x:400,y:400},{x:600,y:600},{x:400,y:800},{x:200,y:600}],color:"#a594c0"},
{p:[{x:200,y:600},{x:400,y:800},{x:0,y:800}],color:"#fa8ecc"},
{p:[{x:800,y:400},{x:800,y:800},{x:400,y:800}],color:"#f6ca29"}
]
window.onload=function(){
var canvas=document.getElementById("canvas");

canvas.width=800;
canvas.height=800;

var context=canvas.getContext("2d");
for(var i=0;i<tangram.length;i++){
draw(tangram[i],context);
}
function draw(piece,cxt){
cxt.beginPath();
cxt.moveTo(piece.p[0].x,piece.p[0].y);
for(var i=1;i<piece.p.length;i++);
cxt.lineTo(piece.p[i].x,piece.p[i].y);
cxt.closePath();

cxt.fillStyle=piece.color;
cxt.fill();

cxt.strokeStyle="black";
cxt.lineWidth=3;
cxt.stroke();

}
}
</script>
</body>
</html>