本文实例为大家分享了JS实现拖拽功能的具体代码，供大家参考，具体内容如下
拖拽的原理：三个事件 onmousedown、onmousemove、onmousemove
1、鼠标按下，触发onmousedown，获取鼠标坐标x,y，获取元素坐标x,y
通过event.clientX、event.clientY获取鼠标位置的坐标
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let x = e.clientX - box.offsetLeft; //鼠标点击坐标距离盒子左边缘的距离let y = e.clientY - box.offsetTop; //鼠标点击坐标距离盒子上边缘的距离 |
2、设置元素left、top值，（元素要设置position:absolute）
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box.style.left = ev.clientX - x + 'px';box.style.top = ev.clientY - y + 'px'; |
3、放开鼠标取消dom事件
下面是详细代码：我只开了横向移动
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<!DOCTYPE html><html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <style> #box { width: 100px; height: 100px; background: red; position: absolute } </style></head> <body style="position: relative;overflow: hidden;"> <div id="box"> </div> <script> window.onload = function () { let box = document.getElementById('box') box.onmousedown = function (ev) { let e = ev || event; let x = e.clientX - box.offsetLeft; //鼠标点击坐标距离盒子左边缘的距离 let y = e.clientY - box.offsetTop; //鼠标点击坐标距离盒子上边缘的距离 document.onmousemove = function (ev) { let e = ev || event; box.style.left = ev.clientX - x + 'px'; box.style.top = ev.clientY - y + 'px'; let bodyScreenX = ev.screenX let bodyClientWidth = document.body.clientWidth document.onmouseup = function (ev) { if (ev.clientX - x < 0) { box.style.left = 0 } else if (bodyScreenX > bodyClientWidth) { box.style.right = 0 box.style.left = bodyClientWidth - 100 + 'px' } document.onmousemove = null; document.onmouseup = null; } } } } </script></body> </html> |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/xr510002594/article/details/91392265
