html

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script type="text/javascript" src="24.js"></script>
<style type="text/css">
body{ margin:0; padding:0;}
</style>
</head>
<body onBlur="draw('canvas');">
<canvas id="canvas" width="400" height="300"></canvas>
</body>
</html>

 

js

// JavaScript Document
function draw(id){
    var canvas = document.getElementById(id);
    var context = canvas.getContext('2d');
    context.fillStyle = "green";
    context.strokeStyle = "#fff";
    context.lineWidth = 5;
    context.fillRect(0,0,400,300);
    context.strokeRect(50,50,180,120);
    context.strokeRect(110,110,180,120);
}

 

效果图：

第24章 canvas绘制矩形_html5