Javascript 接收错误消息：尝试将 focus() 调用到元素 ID 时，“未捕获的类型错误：无法读取 null 的属性‘焦点’”
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Receiving Error Message: "Uncaught TypeError: Cannot read property 'focus' of null" when trying to call focus() to an element ID
提问by Kode_12
I have an element in my DOM where I have attached an ID. I want to call focus on that element after the Page Loads and set it to a css style (border: yellow) to highlight that it's currently focused. This is what I have:
我的 DOM 中有一个元素，我在其中附加了一个 ID。我想在页面加载后调用该元素的焦点并将其设置为 css 样式（边框：黄色）以突出显示它当前处于焦点状态。这就是我所拥有的：
//main.html
<myElement id= 'myEl'>
//main.js
window.setTimeout(function () {
document.getElementById('#myEl').focus();
}, 0);
When I refresh the page I receive this error:
当我刷新页面时，我收到此错误：
Uncaught TypeError: Cannot read property 'focus' of null
未捕获的类型错误：无法读取 null 的属性“焦点”
回答by Zakaria Acharki
That because javascript can't find any element with id='#myEl', remove the extra #in :
那是因为 javascript 找不到任何带有 的元素id='#myEl'，删除额外的#in ：
document.getElementById('#myEl').focus();
_________________________^
Or use jquery selector instead :
或者改用 jquery 选择器：
$('#myEl').focus();
Hope this helps.
希望这可以帮助。
回答by mrbengi
Component ID changes in runtime, so use a class rather than ID, will work, like
组件 ID 在运行时更改，因此使用类而不是 ID 会起作用，例如
$(".ClassName").focus();
回答by devhelp37
Below working code for example reference
下面的工作代码作为示例参考
template code
模板代码
<div class="css-description">description</div>
script code
脚本代码
this.$nextTick(() => {
$(".css-description").focus();
})
