JS 上拉加载

$(document).ready( function(){
$contentLoadTriggered = false;
$("#mainDiv").scroll(function(){
if($("#mainDiv").scrollTop() >= ($("#wrapperDiv").height() - 
   $("#mainDiv").height()) &&   $contentLoadTriggered == false)
   $contentLoadTriggered == false)
{
$contentLoadTriggered = true;
$.ajax({
type: "POST",
url: "LoadOnScroll.aspx/GetDataFromServer",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
async: true,
cache: false,
success: function (msg) {
$("#wrapperDiv").append(msg.d);
$contentLoadTriggered = false;
},
error: function (x, e){
alert("The call to the server side failed. " +
x.responseText);
}
}
);
}
}
);
}
);

　　

var range = 50;             //距下边界长度/单位px
    var totalheight = 0; 
    var num ={$data|count};
    var is_load =true;
    var main = $("#con");                     //主体元素
    $(window).scroll(function(){
        var srollPos = $(window).scrollTop();    //滚动条距顶部距离(页面超出窗口的高度)
        totalheight = parseFloat($(window).height()) + parseFloat(srollPos);
        if(($(document).height()-range) <= totalheight && is_load == true) {
            if(num < 5 ){
                return false;
            }       
            is_load = false;
            $("#loading").show();
            //alert("0000");
             $.ajax({
                 url : '{:u("Index/post_json")}',
                 type : 'post',
                 data : {"num":num,"sch_time":sch_time,"city_from":city_from,"city_dst":city_dst},
                 dataType : 'json',
                 success : function(msg) {
                     //alert(msg);
                     $("#loading").hide();
                     myobj=eval(msg); 
                     
                     if(num == myobj['nums']){
                         alert("已经没有新订单了");
                         is_load = false;    //停止加载
                         return false;
                     }else{
                         num=myobj['nums'];
                     }
                     myobjs=myobj['data'];
                     for(var i=0;i<myobjs.length;i++){
                         ht='<div class="trip_li">';
                         ht+='<img class="hot" src="__ROOT__/Public/images/icon_hot.png">';
                         if(myobjs[i]['fleet'].join_uf == 1){
                             ht+='<img class="uf" src="__ROOT__/Public/images/icon_uf.png">';
                         }
                         ht+='<button type="button" class="bespoke" onclick=javascript:window.location.href="'+"{:u('Index/order')}"+'/scid/'+myobjs[i].id+'">立即预约</button>';
                         ht+='<dl>';
                         ht+='<dt><font>'+myobjs[i].from_city+'</font>　<img  src="__ROOT__/Public/images/icon_go.png" />　<font>'+myobjs[i].dst_city+'</font></dt>';
                         ht+='<dd>发车时间：<i class="times">'+myobjs[i].sch_time+'</i></dd>';
                         ht+='<dd>车型：'+myobjs[i]['fleet'].best_car+'</dd>';
                         ht+='<dd><i class="red">￥'+myobjs[i].money+'</i>    <i class="red">空位数: '+myobjs[i].used+'/'+myobjs[i].seat+'</i> </dd>';
                         ht+='</dl>';
                         ht+='</div>';
                         //alert(ht);
                          main.append(ht);
                          
                     } 
                     is_load =true; //恢复加载功能
                     
                 }
             });
            
        }
    });