Question

我有一个用以下数据动态填充JSON数据的选择：元素，1,2,3 ...一旦被选中，选择被隐藏，因为再次显示一个按钮，但我无法显示它元素值，用用户选择的值显示，如何从Javascript中更改select的值？ HTML

using (var context = new VASTEntities())
{
    var query = context.APLCN_TRCKR;
    foreach(var filter in filters)
    {
        query = query.Where(filter);
    }

    var result = query.ToList();
    if (result.Count() == 0)
    {
        throw new Exception("No Applications Found.");
    }
    foreach (var a in result)
    {
        searchAppsObj.Add(Translator.TranslateReqObjToBO.TranslateDTOToSearchApp(a));
    }
    context.Connection.Close();
    return searchAppsObj;
}

Javascript选择：

 <div id="tablaSelect">
    <table id=tabla2 style="width:80%" >
    <tr>  
      <th>
        <div class="styled-select">
          <select class="select" id="boards">
          </select>
        </div>
     </th>
    </tr>
   </table>

改变Javascript

$('#boards')
  .append($("<option></option>")
  .attr("value",'')
  .text("Eelement")); 

$.each(boards, function(index, value) {
     $('#boards')
        .append($("<option></option>")
        .attr("value",value.id)
        .text(value.name)); 
     arrayBoards.push(value.id);
});

Answer 1

如果有一个带有该值的选项（并查看您的代码，那么）document.getElementById("select").value = '';会有效，但该元素的id为boards，不是select：

＆＃13;

$('#boards')
  .append($("<option></option>")
  .attr("value",'')
  .text("Eelement"));

var boards = [
  {id: 1, name: "One"},
  {id: 2, name: "Two"},
  {id: 3, name: "Three"},
  {id: 4, name: "Four"}
];
var arrayBoards = [];

$.each(boards, function(index, value) {
     $('#boards')
        .append($("<option></option>")
        .attr("value",value.id)
        .text(value.name)); 
     arrayBoards.push(value.id);
});

function cambiar(value){
     document.getElementById("tablaSelect").style.display="block";
     document.getElementById("boards").value = value;
}

cambiar("1");
setTimeout(function() {
  cambiar("");
}, 800);

＆＃13;

<div id="tablaSelect">
  <table id=tabla2 style="width:80%" >
  <tr>  
    <th>
      <div class="styled-select">
        <select class="select" id="boards">
        </select>
      </div>
   </th>
  </tr>
 </table>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

＆＃13;

或者，既然您正在使用jQuery，请使用其val：$("#boards").val("");

＆＃13;

$('#boards')
  .append($("<option></option>")
  .attr("value",'')
  .text("Eelement"));

var boards = [
  {id: 1, name: "One"},
  {id: 2, name: "Two"},
  {id: 3, name: "Three"},
  {id: 4, name: "Four"}
];
var arrayBoards = [];

$.each(boards, function(index, value) {
     $('#boards')
        .append($("<option></option>")
        .attr("value",value.id)
        .text(value.name)); 
     arrayBoards.push(value.id);
});

function cambiar(value){
     document.getElementById("tablaSelect").style.display="block";
     $("#boards").val(value);
}

cambiar("1");
setTimeout(function() {
  cambiar("");
}, 800);

＆＃13;

<div id="tablaSelect">
  <table id=tabla2 style="width:80%" >
  <tr>  
    <th>
      <div class="styled-select">
        <select class="select" id="boards">
        </select>
      </div>
   </th>
  </tr>
 </table>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

＆＃13;

Answer 2

是您可以像这样动态更改下拉列表的值

function cambiar(){
     document.getElementById("tablaSelect").style.display="block";
     $("#boards").val(Any value here);
}

更改选择值Javascript

2 个答案: