概述
 HTMLElement.focus()方法可以设置指定元素获取焦点。
语法
element.focus();
示例
text输入框获取焦点
JavaScript
focusMethod = function getFocus() {
  document.getElementById("myTextField").focus();
}HTML
<input type="text" id="myTextField" value="Text field.">
<p></p>
<button type="button" onclick="focusMethod()">点击我让输入框获取焦点</button>Result
按钮获取焦点
JavaScript
focusMethod = function getFocus() {
  document.getElementById("myButton").focus();
}HTML
<button type="button" id="myButton">Click Me!</button>
<p></p>
<button type="button" onclick="focusMethod()">点击我让按钮获取焦点</button>Result
规范
| Specification | Status | Comment | 
|---|---|---|
| WHATWG HTML Living Standard focus | Living Standard | |
| HTML5.1 focus | Recommendation | |
| HTML5 focus | Recommendation | |
| Document Object Model (DOM) Level 2 HTML Specification focus | Recommendation | |
| Document Object Model (DOM) Level 1 Specification focus | Recommendation | 
提示
如果点击事件使用HTMLElement.focus()方法,需要使用event.preventDefault()来让焦点移除当前dom。
规范
DOM Level 1 HTML: various elements.focus
DOM Level 2 HTML: various elements.focus