实现上拉加载最普遍的方式就是监听滚动条的滚动事件，而移动端的下拉刷新利用的是transform属性来进行位移，那用下拉刷新的方式实现上拉加载怎么样?
html结构
<div> <div> </div> </div> <div> <div> </div> </div>
这里我们做了两个主要的盒子，在两个盒子内实现上拉加载。结构很简单。
css样式
* { margin: 0; padding: 0; } .main-box { background: skyblue; width: 100%; height: 300px; overflow: hidden; } .popup-box { width: 100%; } .item { width: 100%; line-height: 40px; text-align: center; padding: 20px; box-sizing: border-box; } .tips{ text-align: center; } #box2 { margin-top: 50px; }
最外面的盒子设置overflow: hidden;中间盒子不设置高度，靠子盒子item撑起。
js代码
/*下拉加载*/ function tDscroll(obj) { this.key = true; //防止重复的请求 this.dom = obj.dom; //传入的dom this.fn = obj.fn; //回调函数 this.outDom = this.dom.querySelector(".popup-box"); //获取内容盒子 this.showHeight = dom.offsetHeight; //显示的高度 this.actualHeight = this.outDom.offsetHeight; //获取实际高度的内容 this.startY = 0; //起始点击位置 this.changedY = 0; //手指移动的距离 this.originY = 0; //偏移量 var that = this; this.dom.addEventListener("touchstart",function (ev) { that.onStart(ev); }); this.dom.addEventListener("touchmove",function (ev) { that.onMove(ev); }); this.dom.addEventListener("touchend",function (ev) { that.onEnd(ev); }); this.fn.call(this,this.outDom); }; tDscroll.prototype.onStart = function (ev) { this.startY = ev.targetTouches[0].clientY; var tempArr = window.getComputedStyle(this.outDom).transform.split(","); if (tempArr.length > 2) { this.originY = parseInt(tempArr[tempArr.length - 1]) || 0; } }; tDscroll.prototype.onMove = function (ev) { this.changedY = ev.touches[0].clientY - this.startY; var changNum = (this.originY + this.changedY); var scrollHeight = -changNum + this.showHeight; if (changNum > 50)return; if (scrollHeight > this.actualHeight + 50)return; if (scrollHeight > this.actualHeight - 50 && this.key) { this.fn.call(this,this.outDom); } this.outDom.style.cssText = "transform: translateY(" + changNum + "px);"; }; tDscroll.prototype.onEnd = function() { if ((this.originY + this.changedY) > 50 ) { this.outDom.style.cssText = "transform: translateY(0px);transition:all .3s"; } if (-(this.originY + this.changedY) + this.showHeight > this.actualHeight + 50) { this.outDom.style.cssText = "transform: translateY(-"+(this.actualHeight - this.showHeight)+"px);transition:all .3s"; } }; var dom = document.querySelector("#box1"); //获取dom var dom2 = document.querySelector("#box2"); //获取dom var obj = { dom : dom, fn : add }; var obj2 = { dom : dom2, fn : add }; new tDscroll(obj); new tDscroll(obj2); var page = 0; //当前的页数(模拟用) // 模拟ajax function add(outDom) { var that = this; this.key = false; var str = ""; for (var i = 1;i < 11;i++) { str+="<div>"+(i+((page)*10))+"</div>" } page++; setTimeout(function () { var tips = outDom.querySelector(".tips"); //获取提升 tips && outDom.removeChild(tips); //如果不是第一次 添加 str += "<div>加载更多</div>"; outDom.innerHTML += str; that.actualHeight = outDom.offsetHeight; that.key = true; },2000) }
原理也是很简单，监听手势事件判断是否距离足够，足够就可以添加数据啦~~~