将显示Select2值，但实际上为空

Question

​

<div class="form-group">
  <select class="form-control js-example-basic-multiple"
    name="regular[]" id="regular" multiple="multiple" required>
    <option value="History">History</option>
    <option value="Political Science">Political Science
    </option>
    <option value="Economics">Economics</option>
    <option value="Education">Education</option>
    <option value="Philosophy">Philosophy</option>
    <option value="Elective Assamese">Elective Assamese
    </option>
    <option value="Elective Hindi">Elective Hindi</option>
    <option value="Arabic">Arabic</option>
    <option value="Mathematics">Mathematics</option>
    <option value="Linguistics">Linguistics</option>
  </select>
</div>

​

这是我的select2输入。

$(document).ready(function () {
    $('#regular').select2({
        placeholder: 'Select any two from the options',
        maximumSelectionLength: 2,
    });
});

我已经在这里加载了select2.js。我正在从ajax调用中获取数据。

options = data.regular.split(",");

这个option有3个值，我想从数组中选择前两个。因此我的代码是..

option = [options[0],options[1]];
$("#regular").val(option).trigger('change');

现在，选项显示在列表中。但是如果我点击并从输入中选择，一切都会重置，我必须再次选择。如果不更改任何我想要提交的内容，该字段将显示为required。

Answer 1

这里的代码之所以有效，是因为来自服务器的值与选项元素的两个值相同

因此，您的问题可能是选项字符串不存在

，它也是大小写敏感的，所以“阿拉伯语”!==“阿拉伯语”阿拉伯语将不起作用

更改选项标记或更改JSON响应中的值字符串

希望这能对?有所帮助

​

$(document).ready(function() {

  mySelect = $('#regular').select2({
    placeholder: 'Select any two from the options',
    maximumSelectionLength: 2
  });

  options = 'Economics,Arabic,Education'.split(',');
  option = [options[0],options[1]];

  //simulate ajax using timeout
  setTimeout(function() {
    mySelect.val(option).trigger("change");
  }, 1000);

});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/select2@4.0.13/dist/css/select2.min.css" rel="stylesheet" />
<script src="https://cdn.jsdelivr.net/npm/select2@4.0.13/dist/js/select2.min.js"></script>
<div class="form-group">
  <select class="form-control js-example-basic-multiple" name="regular[]" id="regular" multiple="multiple" required>
    <option value="History">History</option>
    <option value="Political Science">Political Science
    </option>
    <option value="Economics">Economics</option>
    <option value="Education">Education</option>
    <option value="Philosophy">Philosophy</option>
    <option value="Elective Assamese">Elective Assamese
    </option>
    <option value="Elective Hindi">Elective Hindi</option>
    <option value="Arabic">Arabic</option>
    <option value="Mathematics">Mathematics</option>
    <option value="Linguistics">Linguistics</option>
  </select>
</div>

​