<div class="layui-form-item">
  <label class="layui-form-label">選擇框</label>
  <div class="layui-input-block">
   <select id="t" name="quiz2">
    <option value="">請選擇市</option>
    <option value="2">杭州2</option>
    <option value="3">杭州3</option>
    <option value="4">杭州4</option>
    <option value="5">杭州5</option>
   </select>
  </div>
 </div>

<script>
  // 遍歷select
  $("#t").each(function() {
    // this代表的是<option></option>，對option再進行遍歷
    $(this).children("option").each(function() {
      // 判斷需要對那個選項進行回顯
      if (this.value == 2) {
        console.log($(this).text());
        // 進行回顯
        $(this).attr("selected","selected");
      }
    });
  })
</script>

public String getApiInfoByTypePage(@PathVariable String type, Model model, HttpServletRequest request) {
    List<DopApiType> typeList1 = apiService.findApiTypeByPid(1);
    log.error(typeList1);
    model.addAttribute("typeList1", typeList1);
}

<div class="layui-input-inline">
      <select id="quiz1" name="quiz1" lay-filter="quiz1">
        <option value="1">請選擇一級服務目錄</option>
        <option th:each="list1:${typeList1}" th:value="${list1.typeId}" th:text="${list1.typeName }"></option>
      </select>
    </div>
    <div class="layui-input-inline" lay-filter="inline1">
      <select id="quiz2" name="quiz2" lay-filter="quiz2">
        <option value="0">請選擇二級服務目錄</option>
      </select>
    </div>

 //監(jiān)聽一級服務目錄下拉列表的選擇時間
    form.on('select(quiz1)', function (data) {
      
      var pId = data.value;// 一級列表的id
      $.post('/getApiTypeByPid', {'pId': pId, '': 2}, function (msg) {// 請求二級列表的數(shù)據(jù)
        // console.log(msg);
        $('#quiz2').empty();// 將二級列表的內(nèi)容清空
        for (var i in msg) {// 遍歷數(shù)據(jù)賦值給二級列表的內(nèi)容
          var $content = $('<option value="' + msg[i].typeId + '">' + msg[i].typeName + '</option>');
          $('#quiz2').append($content);
        }
        form.render('select');// 注意：數(shù)據(jù)賦值完成之后必須調(diào)用該方法，進行l(wèi)ayui的渲染，否則數(shù)據(jù)出不來
      });
    });

// 服務目錄的數(shù)據(jù)回顯
    var sesType = [[${type}]];
    var sesType1 = [[${type1}]];// 一級目錄id
    var sesStatus = [[${status}]];
    // 一級目錄回顯
    $("#quiz1").each(function () {// 遍歷select
      $(this).children("option").each(function () {// 遍歷option
        if (this.value == sesType1) {// 跟后臺傳過來的id相同就顯示selected
          // console.log("一級目錄"+$(this).text());
          $(this).attr("selected", "selected");
          $.post('/getApiTypeByPid', {'pId': sesType1, '': 2}, function (msg) {// 根據(jù)一級目錄的id獲取二級目錄的信息
            // console.log(msg);
            $('#quiz2').empty();// 清空
            for (var i in msg) { // 遍歷，進行賦值
              if (msg[i].typeId == sesType) {// 判斷要回顯的二級目錄
                var $content1 = $('<option value="' + msg[i].typeId + '" selected="selected">' + msg[i].typeName + '</option>');
                $('#quiz2').append($content1);
              } else {
                var $content = $('<option value="' + msg[i].typeId + '">' + msg[i].typeName + '</option>');
                $('#quiz2').append($content);
              }
 
            }
            form.render('select');// 注意：一定要調(diào)用該方法進行中心渲染，否則數(shù)據(jù)是顯示不出來的
          });
        }
      });
    });