我的使用引导多重选择的下拉列表没有填充

Question

我正在尝试使用引导javascript和CSS文件创建多选下拉列表。 不幸的是，我动态创建的一组选项（使用AJAX）似乎没有填充列表。

我知道它必须与多选功能有关，因为当我将其设置为单选下拉列表时，它的效果很好。

我想知道它是否与何时调用此函数有关。 当文档准备就绪时，不调用列表，而是在ajax调用成功之后调用。

这是代码：

 function Participants(sid){ console.log(sid); $('#participants').empty() $('#participants').append("<option>Loading......</option>"); $.ajax({ method:"POST", url:"participants_dropdown.php?sid="+sid, contentType:"application/json; charset=utf-8", dataType:"json", success: function(data){ console.log('success') $('#participants').empty(); $('#participants').append("<option value='0'>---Select Participants---</option>"); $.each(data, function(i, item){ $('#participants').append('<option value="'+data[i].facility_id+'">Call-Sign: '+data[i].call_sign+' - Operator: '+data[i].operator+' - Primary Programming: '+data[i].primary_programming+'</option>'); }); }, complete: function(){ } }); $('#participants').multiselect('destroy'); $('#participants').multiselect(); } 

 <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/css/bootstrap-multiselect.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/js/bootstrap-multiselect.js"></script> <div class="col-md-4"> <h3><span>2) Select Market Participants</span></h3> <select id="participants" multiple class="form-control"> </select> </div> <!---sample JSON [{"operator":"Nexstar Media Group Inc","owner":"Mission Broadcasting Inc","call_sign":"KRBC-TV","facility_id":"306","primary_programming":"NBC"},{"operator":"Nexstar Media Group Inc","owner":"Nexstar Media Group Inc","call_sign":"KTAB-TV","facility_id":"59988","primary_programming":"CBS"},{"operator":"Prime Time Christian Broadcasting Incorporated","owner":"Prime Time Christian Broadcasting Incorporated","call_sign":"KPCB-DT","facility_id":"77452","primary_programming":"REL"},{"operator":"Sinclair Broadcast Group Inc","owner":"Sinclair Broadcast Group Inc","call_sign":"KTXS-TV","facility_id":"308","primary_programming":"ABC"},{"operator":"TEGNA Inc","owner":"TEGNA Inc","call_sign":"KXVA","facility_id":"62293","primary_programming":"FOX"}]---> 

任何指导将不胜感激。 我尝试了类似帖子中建议的各种解决方案，但没有运气。

Answer 1

在您的参与者函数中，您有一个ajax调用。 因为这是一个异步调用，所以您需要在成功片段内移动destroy并创建multiselect ：

function Participants(sid){
     console.log(sid);
     $('#participants').empty()
     $('#participants').append("<option>Loading......</option>");
     $.ajax({
         method:"POST",
         url:"participants_dropdown.php?sid="+sid,
         contentType:"application/json; charset=utf-8",
         dataType:"json",
         success: function(data){
             console.log('success')
             $('#participants').multiselect('destroy');
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ HERE
             $('#participants').empty();
             $('#participants').append("<option value='0'>---Select Participants---</option>");
             $.each(data, function(i, item){
                 $('#participants').append('<option value="'+data[i].facility_id+'">Call-Sign: '+data[i].call_sign+' - Operator: '+data[i].operator+' - Primary Programming: '+data[i].primary_programming+'</option>');
          });
             $('#participants').multiselect();
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ HERE
         },
         complete: function(){
         }
     });
 }

代码段（该按钮模拟ajax调用）：

 $('#participants').empty() $('#participants').append("<option>Loading......</option>"); $('#participants').multiselect(); $('#btn').on('click', function(e) { var data = [{"operator":"Nexstar Media Group Inc","owner":"Mission Broadcasting Inc","call_sign":"KRBC-TV","facility_id":"306","primary_programming":"NBC"},{"operator":"Nexstar Media Group Inc","owner":"Nexstar Media Group Inc","call_sign":"KTAB-TV","facility_id":"59988","primary_programming":"CBS"},{"operator":"Prime Time Christian Broadcasting Incorporated","owner":"Prime Time Christian Broadcasting Incorporated","call_sign":"KPCB-DT","facility_id":"77452","primary_programming":"REL"},{"operator":"Sinclair Broadcast Group Inc","owner":"Sinclair Broadcast Group Inc","call_sign":"KTXS-TV","facility_id":"308","primary_programming":"ABC"},{"operator":"TEGNA Inc","owner":"TEGNA Inc","call_sign":"KXVA","facility_id":"62293","primary_programming":"FOX"}]; $('#participants').multiselect('destroy'); $('#participants').empty(); $('#participants').append("<option value='0'>---Select Participants---</option>"); $.each(data, function(i, item){ $('#participants').append('<option value="'+data[i].facility_id+'">Call-Sign: '+data[i].call_sign+' - Operator: '+data[i].operator+' - Primary Programming: '+data[i].primary_programming+'</option>'); }); $('#participants').multiselect(); }) 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/css/bootstrap-multiselect.css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/js/bootstrap-multiselect.js"></script> <div class="col-md-4"> <h3><span>2) Select Market Participants</span></h3> <select id="participants" multiple class="form-control"> </select> <button id="btn" class="btn btn-primary">Click Me</button> </div>