Window: focus event
当元素获得焦点时, focus
事件就会触发。
与 focus
相反的事件是 blur
Bubbles(支持冒泡) | No |
---|---|
Cancelable(可撤销) | No |
Interface(接口) | FocusEvent |
Event handler property(事件处理程序属性) | onfocus |
Sync / Async(同步/异步) | Sync |
Composed(可组成) | Yes |
示例
在线示例
本示例在失去焦点时更改文档的外观。它使用 addEventListener()
监听 focus
和 blur
事件。
HTML
<p id="log">Click on this document to give it focus.</p>
CSS
.paused {
background: #ddd;
color: #555;
}
JavaScript
function pause() {
document.body.classList.add('paused');
log.textContent = 'FOCUS LOST!';
}
function play() {
document.body.classList.remove('paused');
log.textContent = 'This document has focus. Click outside the document to lose focus.';
}
const log = document.getElementById('log');
window.addEventListener('blur', pause);
window.addEventListener('focus', play);
结果
规范
Specification |
---|
UI Events # event-type-focus |
HTML Standard # handler-onfocus |
浏览器兼容性
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