<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
canvas {
border: 1px solid #ccc;
}
</style>
</head>
<body>
<canvas width="600" height="400"></canvas>
<script>
var myCanvas = document.querySelector('canvas');
var ctx = myCanvas.getContext('2d');
//ctx.translate(100,100);
//ctx.scale(0.5,1);
//ctx.rotate(Math.PI/6);
var startAngle = 0;
ctx.translate(150,150);
setInterval(function () {
startAngle += Math.PI/180;
ctx.rotate(startAngle);
ctx.strokeRect(-50,-50,100,100);
},500);
</script>
</body>
</html>运行结果如下:
