$(function() { 
  $(".selectpicker").selectpicker({ 
   noneSelectedText : '请选择'//默认显示内容 
  }); 

//数据赋值 
var select = $("#slpk"); 
select.append("<option value='1'>香蕉</option>"); 
select.append("<option value='2'>苹果</option>"); 
select.append("<option value='3'>橘子</option>"); 
select.append("<option value='4'>石榴</option>"); 
select.append("<option value='5'>棒棒糖</option>"); 
select.append("<option value='6'>桃子</option>"); 
select.append("<option value='7'>陶子</option>"); 

//初始化刷新数据 
 $(window).on('load', function() { 
  $('.selectpicker').selectpicker('refresh'); 
 }); 
}); 

<select id="slpk" class="selectpicker" data-live-search="true" multiple></select> 

var selectedValues = [];  
slpk:selected").each(function(){ 
selectedValues.push($(this).val()); 
}); 

$(function() { 
  $(".selectpicker").selectpicker({ 
   noneSelectedText : '请选择' 
  }); 
  $(window).on('load', function() { 
   $('.selectpicker').selectpicker('val', ''); 
   $('.selectpicker').selectpicker('refresh'); 
  }); 
  //下拉数据加载 
  $.ajax({ 
   type : 'get', 
   url : basePath + "/lictran/tranStation/loadRoadForTranStationDetail", 
   dataType : 'json', 
   success : function(datas) {//返回list数据并循环获取 
    var select = $("#slpk"); 
    for (var i = 0; i < datas.length; i++) { 
     select.append("<option value='"+datas[i].ROAD_CODE+"'>" 
       + datas[i].ROAD_NAME + "</option>"); 
    } 
    $('.selectpicker').selectpicker('val', ''); 
    $('.selectpicker').selectpicker('refresh'); 
   } 
  }); 
 });