selectpicker使用，单一默认，多数据默认

<div class="form-group">
            <div id="workingstatusdiv">
                <label class="label-width2">状态</label>
                <input id="workingstatusstate" value="0" type="hidden">
                <input id="workingstatusparameter" value="isstatus" type="hidden">
                <select class="selectpicker displaynone" multiple data-live-search="false" 
                id="workingstatus" name="workingstatus"></select>
            </div>
        </div>

if ($("#workingstatusstate").val() == "0") {       
        $("#workingstatus").append(" <option value='1'>状态1</option> "+
                                   " <option value='2'>状态2</option> "+ 
                                   " <option value='3'>状态3</option>");
               
         //单选 两种都可
         $('#workingstatus').val(["1"]);
         $('#workingstatus').val("1");    
         //多选
         $('#workingstatus').val(["1","2","3"]);
             
         $('#workingstatus').selectpicker('render');
         $('#workingstatus').selectpicker('refresh');
        
        $("#workingstatusstate").val("1");
    }