Element: mouseenter event

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用法注意事项
范例
规范
浏览器兼容性
另请参阅
相关话题

mouseenter event is fired at an 元素 when a pointing device (usually a mouse) is initially moved so that its hotspot is within the element at which the event was fired.

冒泡	No
可取消	No
接口	`MouseEvent`
事件处理程序特性	`onmouseenter`

用法注意事项

Though similar to mouseover , mouseenter differs in that it doesn't bubble and it isn't sent to any descendants when the pointer is moved from one of its descendants' physical space to its own physical space.

One


							mouseenter

event is sent to each element of the hierarchy when entering them. Here 4 events are sent to the four elements of the hierarchy when the pointer reaches the text.

A single


							mouseover

event is sent to the deepest element of the DOM tree, then it bubbles up the hierarchy until it is canceled by a handler or reaches the root.

With deep hierarchies, the number of mouseenter events sent can be quite huge and cause significant performance problems. In such cases, it is better to listen for mouseover 事件。

Combined with the corresponding mouseleave (which is fired at the element when the mouse exits its content area), the mouseenter event acts in a very similar way to the CSS :hover pseudo-class.

范例

mouseover documentation has an example illustrating the difference between mouseover and mouseenter .

mouseenter

The following trivial example uses the mouseenter event to change the border on the div when the mouse enters the space alloted to it. It then adds an item to the list with the number of the mouseenter or mouseleave 事件。

HTML

<div id='mouseTarget'>
 <ul id="unorderedList">
  <li>No events yet!</li>
 </ul>
</div>

CSS

Styling the div to make it more visible.

#mouseTarget {
  box-sizing: border-box;
  width:15rem;
  border:1px solid #333;
}

JavaScript

var enterEventCount = 0;
var leaveEventCount = 0;
const mouseTarget = document.getElementById('mouseTarget');
const unorderedList = document.getElementById('unorderedList');
mouseTarget.addEventListener('mouseenter', e => {
  mouseTarget.style.border = '5px dotted orange';
  enterEventCount++;
  addListItem('This is mouseenter event ' + enterEventCount + '.');
});
mouseTarget.addEventListener('mouseleave', e => {
  mouseTarget.style.border = '1px solid #333';
  leaveEventCount++;
  addListItem('This is mouseleave event ' + leaveEventCount + '.');
});
function addListItem(text) {
  // Create a new text node using the supplied text
  var newTextNode = document.createTextNode(text);
  // Create a new li element
  var newListItem = document.createElement("li");
  // Add the text node to the li element
  newListItem.appendChild(newTextNode);
  // Add the newly created list item to list
  unorderedList.appendChild(newListItem);
}

结果

规范

规范	状态
UI Events The definition of 'mouseenter' in that specification.	工作草案
DOM (文档对象模型) 3 级事件规范 The definition of 'mouseenter' in that specification.	过时

浏览器兼容性

更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`mouseenter` event	Chrome 30	Edge 12	Firefox 10	IE 5.5	Opera 17	Safari 6.1	WebView Android ≤37	Chrome Android 30	Firefox Android 10	Opera Android 18	Safari iOS 6.1	Samsung Internet Android 2.0

图例

完整支持

在此页

用法注意事项

范例

mouseenter

HTML

CSS

JavaScript

结果

规范

浏览器兼容性

图例

另请参阅

相关话题