下拉刷新上拉加载

<div id="MyScroller" class="main">
        <div class="warpper">
            <div id="PullDown" class="scroller-pullDown" style="display: none;">
                <img style="width: 20px; height: 20px;" src="rolling.svg" />
                <span id="pullDown-msg" class="pull-down-msg">下拉刷新</span>
            </div>
            <ul id="Content" class="dropdown-list">
            </ul>
            <div id="PullUp" class="scroller-pullUp" style="display: none;">
                <img style="width: 20px; height: 20px;" src="rolling.svg" />
                <span id="pullUp-msg" class="pull-up-msg">上拉刷新</span>
            </div>
        </div>
    </div>

<style type="text/css">
    body {
        overflow: hidden;
    }
    
    body,
    ul {
        padding: 0;
        margin: 0;
    }

    .main {
        position: relative;
        width: 100%;
        height: 100%;
    }

    .main .warpper {
        position: absolute;
        width: 100%;
    }

    .scroller-pullDown,.scroller-pullUp {
        width: 100%;
        height: 30px;
        padding: 10px 0;
        text-align: center;
    }

    .scroller-pullUp {

    }

    .dropdown-list {
        padding: 0;
        margin: 0;
    }
    
    .dropdown-list li {
        width: 100%;
        background: #ddd;
        line-height: 45px;
        text-align: center;
        color: #FFF;
        border-bottom: 1px solid #FFF;
    }
    </style>

// 模拟数据
    var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 ,19 , 20];

    function getContents() {
        var li = "";
        for (var i = 0; i < arr.length; i++) {
            li += "<li>Item" + arr[i] + "</li>";
        }
        return li;
    }

    function appendContent(content) {
        var ul = document.getElementById(‘Content‘);
        ul.innerHTML = ul.innerHTML + content;
    }
    
    window.onload = function() {

        // 初始化body高度
        document.body.style.height = Math.max(document.documentElement.clientHeight, window.innerHeight || 0) + ‘px‘;
       
        appendContent(getContents());

        var pullDown = document.querySelector("#PullDown"),
            pullUp = document.querySelector("#PullUp"),
            isPulled = false; // 拉动标记

        var myScroll = new IScroll(‘#MyScroller‘, {
            probeType: 3,
            mouseWheel: true,
            scrollbars: true,
            preventDefault: false,
            fadeScrollbars: true
        });

        myScroll.on(‘scroll‘, function() {
            var height = this.y,
                bottomHeight = this.maxScrollY - height;

            console.log("height:" + height);
            console.log("bottomHeight:" + bottomHeight);

            // 控制下拉显示
            if (height >= 60) {
                pullDown.style.display = "block";
                isPulled = true;
                return;
            }
            else if (height < 60 && height >= 0) {
                pullDown.style.display = "none";
                return;
            }

            // 控制上拉显示
            if (bottomHeight >= 60) {
                pullUp.style.display = "block";
                isPulled = true;
                return;
            }
            else if (bottomHeight < 60 && bottomHeight >= 0) {
                pullUp.style.display = "none";
                return;
            }
        })

        myScroll.on(‘scrollEnd‘, function() { // 滚动结束
            if (isPulled) { // 如果达到触发条件，则执行加载
                isPulled = false;
                appendContent(getContents());
                myScroll.refresh();
            }
        });
    }