<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>canvas</title>
<script type="text/javascript" src="../js/jQuery.js"></script>
<style type="text/css">
*{
margin: 0;
padding: 0;
outline: none;
border: none;
}
#canvas{
margin: auto auto;
width: 7rem;
margin: .25rem 0 0 1.5rem;
border: 1px solid black;
}
</style>
</head>
<body>
<canvas id="canvas" width="1000" height="600"></canvas>
</body>
</html>
<script type="text/javascript">
/**
* rem 布局初始化
*/
$('html').css('font-size', $(window).width()/10);
/**
* 获取 canvas 画布
* 获取 canvas 绘图上下文环境
*/
var canvas = $('#canvas')[0];
var context = canvas.getContext('2d');
/**
* canvas 填充的图形 ( 一个箭头为例 )
*/
context.beginPath();
context.lineTo(200, 200);
context.lineTo(500, 200);
context.lineTo(500, 100);
context.lineTo(700, 250);
context.lineTo(500, 400);
context.lineTo(500, 300);
context.lineTo(200, 300);
//context.lineTo(200, 200); //当用这种方式封闭的时候, 当线条的粗细较宽时, 会出现瑕疵
context.closePath(); //封闭一个图形, 没有瑕疵, 推荐使用
context.fillStyle = 'yellow'; //填充封闭图形的颜色,
context.fill(); //填充图形 ( 后绘制的图形会覆盖前面的图形, 绘制时注意先后顺序 )
context.lineWidth = 5;
context.stroke(); //填充图形 ( 后绘制的图形会覆盖前面的图形, 绘制时注意先后顺序 )
</script>