···<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>事件</title>
<style>
#box {
width: 400px;
height: 200px;
background-color: red;
position: absolute;
}
</style>
</head>
<body>
<div id="box"></div>
<script>
let box = document.getElementById("box");
box.onmousedown = function(e) {
let ox = e.offsetX;
let oy = e.offsetY;
document.onmousemove = function(e2) {
let cx = e2.clientX;
let cy = e2.clientY;
let _left = cx - ox;
let _top = cy - oy;
let docWidth = document.documentElement.clientWidth;
let docHeight = document.documentElement.clientHeight;
if (_left < 0) {
_left = 0;
}
if (_left > docWidth - box.offsetWidth) {
_left = docWidth - box.offsetWidth;
}
if (_top < 0) {
_top = 0;
}
if (_top > docHeight - box.offsetHeight) {
_top = docHeight - box.offsetHeight;
}
box.style.left = _left + "px";
box.style.top = _top + "px";
};
};
document.onmouseup = function() {
document.onmousemove = null;
};
</script>
</body>
</html>
效果展示
屏幕截图 2025-03-28 135907.png
