jQuery+Canvas 简易画板

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Canvas</title>
    <script src="jQuery.js"></script>
</head>
<style type="text/css">
    body{
        padding: 0;
        margin: 0;
        background: black;
    }
    #canvas{
        background: white;
        margin: 100px 0 0 300px;
    }
    #canvas > span{
        color: white;
        font-size: 14px;
    }
</style>
<body>
    <canvas id="canvas" width="600" height="500">
        <span>您的浏览器不支持</span>
    </canvas>
</body>
</html>
<script type="text/javascript">
    /*获取绘制环境*/    
    var oc = $(‘#canvas‘)[0];
    canvas = oc.getContext(‘2d‘);    
    $(‘#canvas‘).on(‘mousedown‘, function(){
        /*开始绘制*/        
        canvas.beginPath();
        /*设置动画绘制起点坐标*/
        canvas.moveTo(event.pageX - 300 , event.pageY - 100);
        $(‘#canvas‘).on(‘mousemove‘, function(){
            /*设置下一个点坐标*/
            canvas.lineTo(event.pageX - 300 , event.pageY - 100);
            /*画线*/
            canvas.stroke();
        });
    }).on(‘mouseup‘, function(){
        $(‘#canvas‘).off(‘mousemove‘);
    });    
</script>