如何使用Activeform在Yii2中創建依賴下拉菜單？

我有一個形式，其中有2個下拉列表，從第一個下拉列表中選擇批次，並根據該批次，學生將出現在第二個下拉列表中，現在我正在獲取批次下拉列表，但沒有得到使用批次的學生下拉列表如何使用Activeform在Yii2中創建依賴下拉菜單？

這是我的視圖

<?php 
use yii\helpers\Html; 
use yii\widgets\ActiveForm; 
use yii\helpers\ArrayHelper; 
use common\models\TblBetch; 
use common\models\TblCompany; 
use common\models\TblCourse; 
use common\models\TblStudent; 
use common\models\TblStudentExpence; 
use kartik\widgets\DepDrop; 
use yii\db\Query;?><link rel="shortcut icon" href="<?php echo Yii::$app->params['global_theme_path'];?>images/logo1.png" type="image/png"><script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script><script src="http://iamrohit.in/lab/js/location.js"></script><div class="pageheader"><h2><i class="fa fa-money"></i>Expense</h2> 
<div class="breadcrumb-wrapper"> 
    <span class="label">You are here:</span> 
    <ol class="breadcrumb"> 
     <li><a href="dashboard">Westline Shipping</a></li> 
     <li class="active">Add Expense</li> 
    </ol></div></div><div class="contentpanel"> 
<?php 
$session = Yii::$app->session; 
if($session->hasFlash('success')) 
{ 
    echo $session->getFlash('success'); 
} 
if($session->hasFlash('error')) 
{ 
    echo $session->getFlash('error'); 
} 
$site = ''; 
?> 
<div class="row"> 
    <div class="col-md-12"> 
     <div class="container-fluid-50"> 
      <div class="col-md-6"> 
       <div class="panel panel-default"> 
        <div class="panel-heading"> 
         <div class="panel-btns"> 
          <a href="#" class="minimize">&minus;</a> 
         </div> 
         <h4 class="panel-title">Add Expense</h4> 
        </div> 
        <form class="panel-body" action="dashboard" method="post"> 
         <div class="row"> 
          <?php $form = ActiveForm::begin(); ?> 
          <div class="col-sm-9"> 
           <div class="form-group"> 
            <label class="control-label"></label> 
            <?php 
            //$batch = new TblBetch(); 
            //$quer = new Query(); 
            //$getid = ['']; 
            //$getid = $quer->select('b_sn')->from($batch->tableName())->all(); 
            //echo $form->field($model,'se_b_id')->dropDownList($getid,['id'=>'se_b_id']); 
            ?> 
            <?= 
            $form->field($model,'se_s_id')->dropDownList(
             ArrayHelper::map(TblBetch::find()->all(),'b_id','b_sn'), 
             [ 
              'prompt'=>'Select Batch', 
              'name'=>'s_b_id', 
              'id'=>'s_b_id', 
              'onchange'=>'$.post("student?id="+$(this).val(),function(data){$("select#tblstudentexpence-se_s_id").html(data);});' 
             ]); 
            ?> 
           </div> 
          </div><!-- col-sm-6 --> 
          <div class="col-sm-9"> 
           <div class="form-group"> 
            <label class="control-label"></label> 
            <?= 
             $form->field($model,'se_s_id')->dropDownList(
             ArrayHelper::map(TblStudent::find()->all(),'s_id','s_fname'), 
             [ 
              'prompt'=>'Select Student', 
              'name'=>'se_s_id', 
              'id'=>'se_s_id' 
             ]); 
            ?> 

           </div> 
          </div><!-- col-sm-6 --> 
          <div class="col-sm-9"> 
           <div class="form-group"> 
            <label class="control-label">Payment Mode</label> 
            <div class="radio"><label><input type="radio" name="num" value="cash" required> Cash </label></div> 
            <div class="radio"><label><input type="radio" name="num" value="check" required> Check </label></div> 
            <div class="radio"><label><input type="radio" name="num" value="dd" required> DD </label></div> 
           </div> 
          </div><!-- col-sm-6 --> 
          <div class="col-sm-9"> 
           <div class="form-group"> 
            <label class="control-label">Check/DD No</label> 
            <input type="text" name="num" id="num" class="form-control" placeholder="Enter your check or DD number" required/> 
           </div> 
          </div><!-- col-sm-6 --> 
          <div class="col-sm-9"> 
           <div class="form-group"> 
            <label class="control-label">Amount</label> 
            <input type="text" name="lastname" class="form-control" placeholder="Enter your Amount" required/> 
           </div> 
          </div><!-- col-sm-6 --> 

          <div class="col-sm-9"> 
           <div class="form-group"> <br><br> 
            <input type="submit" value="Submit" class="btn btn-primary"> 
            &nbsp;&nbsp;&nbsp; 
            <input type="reset" value="Cancel" class="btn btn-primary"> 
           </div></div> 
         </div><!-- row --> 
        </form> 
       </div><!-- panel-body --> 

      </div> 
     </div> 

    </div>    <div class="col-md-12"> 

    </div> 

</div></div></div> <script> 
$(function() { 
    window.invalidate_input = function() { 
     if ($('input[name=num]:checked').val() == "check" || $('input[name=num]:checked').val() == "dd") 
      $('#num').removeAttr('disabled'); 
     else 
      $('#num').attr('disabled', 'disabled'); 
    }; 

    $("input[name=num]").change(invalidate_input); 

    invalidate_input(); 
});

這是我的控制器（sitecontroller.php）

public function actionStudent($id) 
{ 
    //p($id); 
     $student = new TblStudent(); 
     $queryobj = new Query(); 
     $data = []; 
     $data = $queryobj->select('*')->from($student->tableName())->where(['s_betch'=>$id])->count(); 
     //p($data); 
     $queryobj1 = new Query(); 
     $getid = []; 
     $getid = $queryobj->select('*')->from($student->tableName())->where(['s_betch'=>$id])->all(); 
     //p($getid); 
     if($data > 0) 
     { 
      foreach($getid as $gid) 
      { 
       echo "<option value='".$gid->s_id."'>".$gid->s_fname."</option>"; 
      } 
     } 
     else 
     { 
      echo "<option> - </option>"; 
     } 
}