yii2 kartik export不下载过滤结果

Question

我是Yii的新手，我已经安装了kartik导出扩展程序。当我以任何格式点击导出时，我没有收到任何错误，而是获得“生成导出文件。请稍候......”。我等了很多个小时，但我的过滤结果数据没有下载。

请检查我的代码：

 public function actionProductivity()
{
    $model = new EmployeeJobs();
    $dataProvider = '';

    if(isset($_GET['EmployeeJobs']))
    {

        $model->load(Yii::$app->request->get());
        $strt='';
        $from='';
        $end ='';
        $to ='';
        $start =  $model->start_date ;
        $from  =   ( $start )? \DateTime::createFromFormat('d-m-Y', $start )->format('Y-m-d') : '';
        $end = $model->end_date;
        $to       =   ( $end )? \DateTime::createFromFormat('d-m-Y', $end )->format('Y-m-d') : '';


    $sql ="SELECT employee.employee_name As Name,sum(distinct employee_jobs.sold_hour) As Sold_hour,
            sum(distinct employee_jobs.actual_hour)As Actual_hr,
            employee.id As emp_id,sum(distinct login_history.end_time) As login_hr,
            (sum(distinct employee_jobs.sold_hour)/sum(distinct login_history.end_time)*100) As Productivity
        FROM employee
        LEFT OUTER JOIN employee_jobs ON employee_jobs.employee_id = employee.id
        LEFT OUTER JOIN login_history ON login_history.employee_id = employee.id
        WHERE employee_jobs.job_status>4
        AND employee_jobs.sold_hour IS NOT NULL
       ";

         if( $from != '')
        {
            $sql .= " AND employee_jobs.updated_time >= '{$from}' ";
            $sql .= "AND login_history.logout_time >='{$from}'";
        }
        if($model->employee_id !='')
        {
            $sql.=" AND  employee_jobs.employee_id={$model->employee_id}";
            $sql.=" AND  login_history.employee_id={$model->employee_id}";
        }
        if( $to != '')
        {
            $sql .= " AND employee_jobs.updated_time <= '{$to}' ";
            $sql .= "AND login_history.logout_time <='{$to}'";
        }

        $sql .= " GROUP BY employee.id ";
        $dataProvider   =  new SqlDataProvider([
                'sql'           =>  $sql,

                ]);

        return $this->render('productivity_report',
                [   'model'         => $model,
                    'dataProvider'  => $dataProvider,
                ]);
    }

视图/ productivity_report

  <?php

use yii\helpers\Html;
use yii\widgets\ActiveForm;
use app\models\Employee;
use yii\helpers\ArrayHelper;
use kartik\date\DatePicker;
use kartik\select2\Select2;
use yii\widgets\DetailView;
// use yii\grid\GridView;
use kartik\export\ExportMenu;
use kartik\grid\GridView;
/* @var $this yii\web\View */
/* @var $model app\models\EmployeeJobsSearch */
/* @var $form yii\widgets\ActiveForm */
?>

<div class="employee-jobs-search">

    <?php $form = ActiveForm::begin([
        'action' => ['productivity'],
        'method' => 'get',
    ]); ?>
<h1> Productivity Report</h1>
<div class ="row">
    <div class="col-md-3">

      <?php 

      $data = ArrayHelper::map(Employee::find()->all(), 'id','employee_name');
      echo $form->field($model, 'employee_id')->widget(Select2::classname(), [
    'data' => $data,
    'language' => 'de',
    'options' => ['placeholder' => 'Select Employee ...'],
    'pluginOptions' => [
        'allowClear' => true
    ],
    ]);
 ?>


        </div>
        <div class="col-md-3">
         <label> Start Date</label>
     <?php
            echo DatePicker::widget([
            'model' => $model, 
            'attribute' => 'start_date',
            'options' => ['placeholder' => 'Enter  date '],
            'pluginOptions' => [
                'autoclose'=>true,
                'format' =>'d-m-yyyy'
            ]
                ]); 
    ?>
    </div>
    <div class="col-md-3">
    <label>End Date </label>
     <?php
            echo DatePicker::widget([
            'model' => $model, 
            'attribute' => 'end_date',
            'options' => ['placeholder' => 'Enter  date '],
            'pluginOptions' => [
                'autoclose'=>true,
                'format' =>'d-m-yyyy'
            ]
                ]); 
    ?>

   </div>
   </div>

    <div class="form-group">
        <?= Html::submitButton(Yii::t('app', 'Search'), ['class' => 'btn btn-primary']) ?>
        <?= Html::resetButton(Yii::t('app', 'Reset'), ['class' => 'btn btn-default']) ?>
    </div>

<div class="col-md-10">

       <?php     $gridColumns  = [
        ['class' => 'kartik\grid\SerialColumn'],
            'Name',
           'Sold_hour',

            ['header'=>' Available Hour',
            'value'=> function($data)
            {

                return round($data['login_hr'],2);
            }

           ],


          ['header'=>'Productivity ',
            'value'=> function($data)
            {

                return round($data['Productivity'],2);
            }

           ],



        ];
        ?>



</div>

<?php 
    if( $dataProvider != '' ) :
    echo ExportMenu::widget([
        'dataProvider' => $dataProvider,
        'columns' => $gridColumns,
        'fontAwesome' => true,
        'dropdownOptions' => [
            'label' => 'Export All',
            'class' => 'btn btn-default'
        ]
    ]) . "<hr>\n".
    GridView::widget([
        'dataProvider' => $dataProvider,
        'columns' => $gridColumns,
    ]);
    endif;
?>
    <?php ActiveForm::end(); ?>

</div>

请帮帮我......