JS canvas 小实例

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
	</head>
	<body>
		<canvas id="area" style="width:600px;height:300px;">
			<b style="color:red;">你的浏览器不支持此标签</b>
		</canvas>
		<script>
			var c = document.getElementById("area");
			var ctx = c.getContext("2d");
			ctx.beginPath();
			ctx.arc(70,70,40,0,Math.PI*2,false);
			ctx.stroke();
		</script>
	</body>
</html>