<!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{
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 cxt = canvas.getContext('2d');
/**
* 文字的对齐
* textAlign: left center right
*/
/*
cxt.fillStyle = "blue";
cxt.font = "bold 40px sans-serif";
cxt.textAlign = "left";
cxt.fillText("Hello Canvas", 500, 200);
cxt.textAlign = "center";
cxt.fillText("Hello Canvas", 500, 300);
cxt.textAlign = "right";
cxt.fillText("Hello Canvas", 500, 400);
cxt.moveTo(500, 0);
cxt.lineTo(500, 600);
cxt.stroke();
*/
/*
* 文字对齐
* textBaseLine: top, middle, bottom, alphabetic(拉丁文字), ideographic(汉字), hanging(印度文字)
*/
cxt.fillStyle = "blue";
cxt.font = "bold 40px sans-serif";
cxt.textBaseline = "top";
cxt.fillText("Hello Canvas", 100, 100);
cxt.textBaseline = "middle";
cxt.fillText("Hello Canvas", 100, 300);
cxt.textBaseline = "bottom";
cxt.fillText("Hello Canvas", 100, 500);
cxt.moveTo(0, 100);
cxt.lineTo(1000, 100);
cxt.moveTo(0, 300);
cxt.lineTo(1000, 300);
cxt.moveTo(0, 500);
cxt.lineTo(1000, 500);
cxt.stroke();
</script>