鼠标按住时mousemove事件不触发廓——setPointerCapture对子元素mousemove事件的影响
阅读代码, 说明为什么鼠标按住时经过子元素子元素的mousemove事件没有触发
html
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Pointer Capture 示例</title>
<style>
#parent {
width: 400px;
height: 400px;
background-color: lightblue;
position: relative;
}
#child {
width: 100px;
height: 100px;
background-color: coral;
position: absolute;
top: 150px;
left: 150px;
}
</style>
</head>
<body>
<div id="parent">
<div id="child"></div>
</div>
<script>
const parent = document.getElementById('parent');
const child = document.getElementById('child');
// 为父元素添加 pointerdown 事件
parent.addEventListener('pointerdown', (event) => {
parent.setPointerCapture(event.pointerId);
console.log('Pointer captured by parent');
// 在 pointerdown 时添加 pointermove 事件监听器
const onPointerMove = (event) => {
console.log('Pointer is moving over the parent');
};
// 将 pointermove 事件监听器与已创建的回调函数相关联
parent.addEventListener('pointermove', onPointerMove);
// 在 pointerup 时移除 pointermove 事件监听器
const onPointerUp = () => {
parent.releasePointerCapture(event.pointerId);
console.log('Pointer released by parent');
parent.removeEventListener('pointermove', onPointerMove);
parent.removeEventListener('pointerup', onPointerUp);
};
// 添加 pointerup 事件监听器
parent.addEventListener('pointerup', onPointerUp);
});
// 为子元素添加 mousemove 事件
child.addEventListener('mousemove', (event) => {
console.log('Pointer is mouse moving over the child');
});
</script>
</body>
</html>