本文實例為大家分享了JS實現(xiàn)拖拽功能的具體代碼，供大家參考，具體內(nèi)容如下
拖拽的原理：三個事件 onmousedown、onmousemove、onmousemove
1、鼠標按下，觸發(fā)onmousedown，獲取鼠標坐標x,y，獲取元素坐標x,y
通過event.clientX、event.clientY獲取鼠標位置的坐標
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let x = e.clientX - box.offsetLeft; //鼠標點擊坐標距離盒子左邊緣的距離let y = e.clientY - box.offsetTop; //鼠標點擊坐標距離盒子上邊緣的距離 |
2、設置元素left、top值，（元素要設置position:absolute）
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box.style.left = ev.clientX - x + 'px';box.style.top = ev.clientY - y + 'px'; |
3、放開鼠標取消dom事件
下面是詳細代碼：我只開了橫向移動
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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; //鼠標點擊坐標距離盒子左邊緣的距離 let y = e.clientY - box.offsetTop; //鼠標點擊坐標距離盒子上邊緣的距離 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內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/xr510002594/article/details/91392265
