<!Doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html";charset="utf-8">
<title>canvas</title>
<script language=javascript>
var i;
var height;
var width;
var context;
function draw()
{
var canvas=document.getElementById('1');
if(canvas==null)
{
return false;
}
context=canvas.getContext('2d');
width=canvas.width;
height=canvas.height;
i=0;
setInterval("rotate()",80);
}
function rotate()
{
context.clearRect(0,0,width,height);
context.fillStyle="blue";
context.fillRect(i,0,20,20);
i+=20;
}
</script>
</head>
<body>
<canvas id="1" style="border: 1px solid skyblue" width="800" height="600">恩？
<script>
draw();
</script>
</canvas>
</body>
</html>
