代码展示：
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>鼠标下拉效果</title>
<style>
#box{
position: absolute;
width: 400px;
height: 300px;
background-color: red;
}
</style>
</head>
<body>
<div id="box"></div>
<script>
let box = document.getElementById("box")
box.onmousedown = function (e) {
let offsetX = e.offsetX
let offsetY = e.offsetY
document.onmousemove = function (e2) {
let clientX = e2.clientX
let clientY = e2.clientY
_left = clientX - offsetX
_top = clientY - offsetY
if(_left<0){
_left = 0
}
if(_top<0){
_top = 0
}
if(_left > document.documentElement.clientWidth - box.offsetWidth){
_left = document.documentElement.clientWidth - box.offsetWidth
}
if(_top > document.documentElement.clientHeight - box.offsetHeight){
_top = document.documentElement.clientHeight - box.offsetHeight
}
box.style.left = _left + "px"
box.style.top = _top + "px"
}
}
document.onmouseup = function () {
document.onmousemove = null
}
</script>
</body>
</html>
图片展示效果：
屏幕截图 2025-03-22 195840.png
学习收获：
1.学会了如何用鼠标拖拽标签
2.学会了如何用不将标签移出浏览网页
