HTML5之转动的轮子
<!doctype html>
<html>
<head></head>
<body>
<canvas width="1000" height="800" style="background:#abcdef" id="canvas">
您的浏览器当前版本不支持canvas标签
</canvas>
<button onclick="clearInterval(s)">Stop interval</button>
<script>
//获取画布DOM 还不可以操作
var canvas=document.getElementById('canvas');
//alert(canvas);
//设置绘图环境
var cxt=canvas.getContext('2d');
//alert(cxt);
var count=0;
function funrac(){
cxt.clearRect(0,0,1000,800);
//画一条线段。
//开启新路径
cxt.beginPath();
cxt.lineWidth=8;
cxt.strokeStyle="#ff9900";
cxt.arc(500,400,100,0,360,false);
cxt.stroke();
cxt.closePath();
for(var i=0;i<12;i++){
cxt.save();
cxt.lineWidth=3;
cxt.translate(500,400);
cxt.rotate(-count+i*30*Math.PI/180);
cxt.beginPath();
cxt.moveTo(0,0);
cxt.lineTo(0,100);
cxt.stroke();
cxt.closePath();
cxt.restore();
}
count++;
}
funrac();
var s = setInterval(funrac,10);
</script>
</body>
</html>
