<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>设置线条的宽度lineWidth</title>
<style>
canvas{
border: 1px dashed gray
}
</style>
<script>
window.onload = function(){
var oCanvas = document.getElementById("canvas");
if(oCanvas.getContext){
var oContext = oCanvas.getContext("2d");
oContext.beginPath();
// 线条默认宽度是1
oContext.lineWidth = 10;
oContext.moveTo(20,20);
oContext.lineTo(200,20);
oContext.stroke();
// 定义线帽样式lineCap
// lineJoin定义两个线条交接处样式
// miterLimit设置或返回最大斜街长度
// setLineDash定义线条虚实样式-数组[线条的长度，间距，第二条的长度，第二条的间距]
}
}
</script>
</head>
<body>
<canvas id="canvas" width="250" height="250"></canvas>
</body>
</html>