<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<canvas id="canvas" style="border: 1px #ddd solid;display: block;margin:0 auto"></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');
context.lineWidth = 5;
context.strokeStyle = "#005588";
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,50,40,0,2*Math.PI*(i+1)/10,false);
context.closePath();
context.stroke()
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,200,40,0,2*Math.PI*(i+1)/10,false);
// context.closePath();
context.stroke()
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,350,40,0,2*Math.PI*(i+1)/10,false);
context.closePath();
context.stroke();
context.fillStyle ="#005588"
context.fill();
}
}else{
alert('当前游览器不支持Canvas，请更换游览器后再试！');
}
}
</script>
</body>
<script>
/*
总结
context.arc(
（圆心x 圆心y 半径r）
centerx,centery,radius,
（起始角度，终止角度）
startingAngle,endingAngle,
(false 顺时针绘制)
anticlockwise = false
)
*/
</script>
</html>
