Ajax实现列表无限加载和二级下拉选项效果

//栏目ajax做加载
public function ajaxlist(){
 //echo "http://www.51sjk.com/Upload/Articles/1/0/280/280622_20210709000948805.php?a=index&c=index&m=ajaxlist";
 //echo "<hr>";
 $data = q('sum');
 $where = array();
 $where['cid'] = 33;
 $rongyulist = m('content')->limit($data,2)->where($where)->select();
 $data['stat'] = 1;
 $data = $rongyulist;
 $this->ajax($data);
 //也可以手动把想要的字段拼接成字符串 
 /*echo "[";
 foreach($rongyulist as $k){
  echo "{"."""."title".""".":".""".$k['title'].""".","."""."description".""".":".""".$k['description'].""".","."""."cid".""".":".""".$k['cid']."""."}".",";  
 }
 echo "]";*/
 }

<script type='text/javascript'>
/*ajax*/
(function(){
//发送数据 
var url = "__web__"+"?a=index&c=index&m=ajaxlist";
var osum = ''; 
$('a.ajaxbut').click(function(){
 osum = $('div.zizhilistcontbox>a').size();
 $.post(url,{sum:osum},function(result){
 console.log(result);
 eval("var info="+result);
 for(var key in info){
   ostr = "<a href='"+"__web__"+"?a=index&c=index&m=content&mid=1&cid=33&aid="+info[key]['aid']+""+"'><h3 class='f100 f16 ts500'>"+info[key]['title']+"</h3><p>"+info[key]['description']+"</p><span class='b parb'></span></a>";
   $('div.zizhilistcontbox').append(ostr);
 };
 });
});
})();
</script>

<!-- 示例：html -->
<dl class="pr keshi" >
 <dt class="pa">科室：</dt>
 <dd class="pa">
  <select name='keshi' class='m_keshi'>
   <option value='0'>--请选择科室--</option>
  </select>
  <select name='zhuanjia' class='m_zhuanjia'>
   <option>--请选择专家--</option>
  </select>
 </dd>
</dl>

//示例控制器
/* ajax请求栏目列表 */
public function ajaxlanmu(){
 $lanmulist = m('category')->where('pid=142')->select();
 $this->ajax($lanmulist);
}
public function ajaxzhuanjia(){
 $where = array();
 $data = q('sum');
 $data = $data ? $data : 143;
 $where['cid'] = $data;
 $zhuanjialist = m('guahao')->where($where)->select();
 $this->ajax($zhuanjialist);
}

<script>
(function(){
var lanmuurl = "__web__"+"?a=index&c=index&m=ajaxlanmu";
var zhuanjiaurl = "__web__"+"?a=index&c=index&m=ajaxzhuanjia";
var osum = ostr = ostr2 = oval = okong = info2 = ocid = '';
/* lanmu */
$.post(lanmuurl,function(result){
 eval("var info="+result);
 for(var key in info){ostr += "<option value='"+info[key]['catname']+"' cid='"+info[key]['cid']+"'>"+info[key]['catname']+"</option>";};
 $('dl.keshi').find('select.m_keshi').append(ostr);
});
/* zhuanjia */
$('dl.keshi').find('select.m_keshi').change(function(){
 oval = $(this).find('option:selected').val();
 if(oval == 0){
  $('dl.zhuanjia').find('select.m_zhuanjia').html("<option>--请选择专家--</option>");
 }else{
  ocid = $(this).find('option:selected').attr('cid');
  $.post(zhuanjiaurl,{sum:ocid},function(result){
   eval("info2="+result);
   ostr2 = '';//注意这里要清空第一次请求的数据
   for(var key2 in info2){
    ostr2 += "<option value='"+info2[key2]['title']+"'>"+info2[key2]['title']+"</option>";    
   };
   $('dl.zhuanjia').find('select.m_zhuanjia').html(ostr2);
  });
 };
});
})();
</script>