设置线条的宽度lineWidth

<!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>