JavaScript实现简单的拖拽效果 JavaScript实现简单的拖拽效果

【JavaScript实现简单的拖拽效果】本文实例为大家分享了JavaScript实现简单的拖拽效果的具体代码，供大家参考，具体内容如下
1.先搭架子：

* {margin: 0; padding: 0; }p {background: skyblue; text-align: center; }html,body {width: 100%; height: 100%; }.mask {width: 100%; height: 100%; position: fixed; left: 0; top: 0; background: rgba(0, 0, 0, .5); display: none; }.login {width: 400px; height: 300px; background: purple; position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); display: none; cursor: move; }.login>span {display: inline-block; width: 50px; height: 50px; background: red; position: absolute; top: 0; right: 0; }

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2.逻辑部分

//1.拿到需要操作的元素const oP = document.querySelector("p"); const oMask = document.querySelector(".mask"); const oLogin = document.querySelector(".login"); const oClose = oLogin.querySelector(".login>span"); // console.log(oClose); //2.监听点击事件oP.onclick = function() {oMask.style.display = "block"; oLogin.style.display = "block"; }; oClose.onclick = function() {oMask.style.display = "none"; oLogin.style.display = "none"; }; //3.监听登录框的按下和移动事件oLogin.onmousedown = function(e) {e = e || e.window; //1.计算固定不变的距离const x = e.pageX - oLogin.offsetLeft; const y = e.pageY - oLogin.offsetTop; // console.log(x); //2.监听移动事件oLogin.onmousemove = function(e) {e = e || e.window; //3.计算移动之后的偏移位let offsetX = e.pageX - x; let offsetY = e.pageY - y; //4.重新设置登录框的位置oLogin.style.left = offsetX + 'px'; oLogin.style.top = offsetY + 'px'; }; }; oLogin.onmouseup = function() {oLogin.onmousemove = null; };