TextMetrics.width
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
只读的 TextMetrics.width 属性，包含文本先前的宽度（行内盒子的宽度），使用 CSS 像素计算。
语法
readonly metrics.width;
示例
事先给定 <canvas> 元素：
html
<canvas id="canvas"></canvas>
你可以使用下面的代码得到一个 TextMetrics 对象：
js
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var text = ctx.measureText("foo"); // TextMetrics object
text.width; // 16;
规范
| Specification |
|---|
| HTML Standard # dom-textmetrics-width-dev |
浏览器兼容性
BCD tables only load in the browser