mouse over和mouse enter区别

在前端开发中，mouse over和mouse enter是两个不同的事件。

mouse over事件触发时，当鼠标光标移动到元素上方时就会触发，无论鼠标是从该元素的子元素移动到该元素上还是直接从其他元素移动到该元素上。

而mouse enter事件触发时，只有在鼠标从元素外部移动到该元素上时才会触发，如果鼠标从该元素的子元素移动到该元素上，该事件不会触发。

因此，mouse enter通常用于处理鼠标移入某个元素的事件，而mouse over通常用于处理鼠标在某个元素上方移动的事件。

相关问题

java swing mouse enter

In Java Swing, the mouse enter event is triggered when the mouse pointer enters a component's boundaries. To handle this event, you can add a MouseListener to the component, and implement the mouseEntered() method.

Here's an example:

JButton button = new JButton("Click me!");

button.addMouseListener(new MouseAdapter() {
    public void mouseEntered(MouseEvent e) {
        // Do something when the mouse enters the button
        button.setText("Hovering over me!");
    }
});

In this example, we add a MouseListener to a JButton. When the mouse enters the button, the mouseEntered() method is called, and we update the button's text to indicate that the user is hovering over it.

You can use this same approach to handle mouse enter events for other Swing components, such as JLabel, JPanel, etc.

const popup = new mapboxgl.Popup({ closeButton: false, closeOnClick: false }); map.on('mouseenter', 'places', e => { // Change the cursor style as a UI indicator. map.getCanvas().style.cursor = 'pointer'; // Copy coordinates array. const coordinates = e.features[0].geometry.coordinates.slice(); const description = e.features[0].properties.description; // Ensure that if the map is zoomed out such that multiple // copies of the feature are visible, the popup appears // over the copy being pointed to. while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) { coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360; } // Populate the popup and set its coordinates // based on the feature found. popup.setLngLat(coordinates).setHTML(description).addTo(map); }); map.on('mouseleave', 'places', () => { map.getCanvas().style.cursor = ''; popup.remove(); }); });给以上代码加详细的中文注释

// 创建一个不带关闭按钮和关闭点击事件的弹出框
const popup = new mapboxgl.Popup({
closeButton: false,
closeOnClick: false
});

// 当鼠标移入 'places' 图层上的元素时触发
map.on('mouseenter', 'places', e => {
// 将鼠标样式更改为指示器
map.getCanvas().style.cursor = 'pointer';

// 复制坐标数组
const coordinates = e.features[0].geometry.coordinates.slice();
const description = e.features[0].properties.description;

// 确保如果地图缩小，多个元素可见，则弹出框出现在指向的副本上
while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) {
coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360;
}

// 填充弹出框并设置其坐标
popup.setLngLat(coordinates).setHTML(description).addTo(map);
});

// 当鼠标移出 'places' 图层上的元素时触发
map.on('mouseleave', 'places', () => {
map.getCanvas().style.cursor = '';
popup.remove();
});