我在font里面添加bold设置字体粗细感觉没效果，是什么原因啊？

来源：6-2 编程练习

xxy流沙

2018-04-29 10:33:04

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>canvas字体</title>
    <style>
        canvas{background-color:lightblue;}
    </style>
</head>
<body>
    <canvas id="canvas" width="800px" height="800px">您的浏览器不支持canvas
    </canvas>
    <script>
        var canvas=document.getElementById("canvas");
        var context=canvas.getContext('2d');
        //此处补充代码
        var str1 = "前端路径课";
        var str2 = "字体的width是：";
        //设置字体
        context.font="30px microsoft yahei";

        //水平方向设置
        context.textAlign = "center";
        //垂直方向设置
        context.textBaselie = "middle";
        //获取字体的宽度
        var width=context.measureText(str1).width;
        var str3=str2+width;
        //填充文本
        context.fillStyle="blue";
        context.fillText(str1,400,400);
        context.fillText(str3,400,500);
    </script>
</body>
</html>