每天一个JavaScript实例-canvas绘图

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>每天一个JavaScript实例-canvas绘图</title>
<style>
	.canvas{
		width:600px;
		height:500px;
	}
</style>

<script>
window.onload = function(){
	var imgcanvas = document.getElementById("imgcanvas");
	if(imgcanvas.getContext){
		var ctx = imgcanvas.getContext('2d');
		ctx.fillStyle="rgba(255,0,0,.1)";
		ctx.strokeStyle = "#000";
		//第一个
		ctx.fillRect(0,0,100,100);
		ctx.strokeRect(0,0,100,100);
		//第二个
		ctx.fillRect(50,50,100,200);

		//第三个
		ctx.strokeRect(80,130,200,100);
	}
}
</script>

</head>

<body>

<canvas class="canvas" id = "imgcanvas">
<p>画布</p>

</canvas>

</body>
</html>