js拖拽排序

转载一篇文带你使用js实现拖拽排序_小杨今天改BUG了么的博客-CSDN博客_js 拖拽排序

 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        * {
            list-style: none;
            margin: 0;
            padding: 0;
        }

        #container {
            width: 500px;
            margin: 100px auto;
        }

        .ele {
            width: 100%;
            height: 40px;
            border: 1px solid #999;
            background: cadetblue;
            margin-top: 2px;
            border-radius: 10px;
            padding-left: 10px;
            color: white;
            cursor: move;
        }
    </style>
</head>
<body>
    <ul id="container">
        <li class="ele" draggable="true">1</li>
        <li class="ele" draggable="true">2</li>
        <li class="ele" draggable="true">3</li>
        <li class="ele" draggable="true">4</li>
    </ul>
    <script>
        var node = document.querySelector("#container");
        var draging = null;
        //使用事件委托,将li的事件委托给ul
        node.ondragstart = function (event) {
            //console.log("start");
            //firefox设置了setData后元素才能拖动!!!!
            //event.target出发事件的元素
            event.dataTransfer.setData("te", event.target.innerText); //不能使用text,firefox会打开新tab
            //event.dataTransfer.setData("self", event.target);
            draging = event.target;
        }
        node.ondragover = function (event) {
            //console.log("onDrop over");
            //取消默认行为
            event.preventDefault();
            var target = event.target;
            //因为dragover会发生在ul上,所以要判断是不是li
            if (target.nodeName === "LI") {
                if (target !== draging) {
                    //getBoundingClientRect()用于获取某个元素相对于视窗的位置集合
                    var targetRect = target.getBoundingClientRect();
                    var dragingRect = draging.getBoundingClientRect();
                    if (target) {
                        if (target.animated) {
                            return;
                        }
                    }
                    if (_index(draging) < _index(target)) {
                        //nextSibling 属性可返回某个元素之后紧跟的节点(处于同一树层级中)。
                        target.parentNode.insertBefore(draging, target.nextSibling);
                    } else {
                        target.parentNode.insertBefore(draging, target);
                    }
                    _animate(dragingRect, draging);
                    _animate(targetRect, target);
                }
            }
        }
        //获取元素在父元素中的index
        function _index(el) {
            var index = 0;

            if (!el || !el.parentNode) {
                return -1;
            }
            //previousElementSibling属性返回指定元素的前一个兄弟元素(相同节点树层中的前一个元素节点)。
            while (el && (el = el.previousElementSibling)) {
                //console.log(el);
                index++;
            }

            return index;
        }

        function _animate(prevRect, target) {
            var ms = 300;

            if (ms) {
                var currentRect = target.getBoundingClientRect();
                //nodeType 属性返回以数字值返回指定节点的节点类型。1=元素节点  2=属性节点
                if (prevRect.nodeType === 1) {
                    prevRect = prevRect.getBoundingClientRect();
                }
                _css(target, 'transition', 'none');
                _css(target, 'transform', 'translate3d(' +
                    (prevRect.left - currentRect.left) + 'px,' +
                    (prevRect.top - currentRect.top) + 'px,0)'
                );

                target.offsetWidth; // 触发重绘
                //放在timeout里面也可以
                // setTimeout(function() {
                //     _css(target, 'transition', 'all ' + ms + 'ms');
                //     _css(target, 'transform', 'translate3d(0,0,0)');
                // }, 0);
                _css(target, 'transition', 'all ' + ms + 'ms');
                _css(target, 'transform', 'translate3d(0,0,0)');

                clearTimeout(target.animated);
                target.animated = setTimeout(function () {
                    _css(target, 'transition', '');
                    _css(target, 'transform', '');
                    target.animated = false;
                }, ms);
            }
        }
        //给元素添加style
        function _css(el, prop, val) {
            var style = el && el.style;

            if (style) {
                if (val === void 0) {
                    //使用DefaultView属性可以指定打开窗体时所用的视图
                    if (document.defaultView && document.defaultView.getComputedStyle) {
                        val = document.defaultView.getComputedStyle(el, '');
                    } else if (el.currentStyle) {
                        val = el.currentStyle;
                    }

                    return prop === void 0 ? val : val[prop];
                } else {
                    if (!(prop in style)) {
                        prop = '-webkit-' + prop;
                    }

                    style[prop] = val + (typeof val === 'string' ? '' : 'px');
                }
            }
        }
    </script>
</body>
</html>

 

posted @ 2022-08-03 15:14  奇迹之耀  阅读(263)  评论(0)    收藏  举报