拖动的文件不会在文件夹中上传

Question

这是我的模型，我已按照我所遵循的教程添加了所需的所有内容。

此代码用于上传所选文件，但不适用于拖动文件。

   <?php

   namespace backend\models;

   use Yii;

   /**
    * This is the model class for table "documents".
    *
    * @property integer $id
    * @property string $ref_id
    * @property string $heading
    * @property integer $doc_type
    * @property string $doc_remarks
    * @property string $doc_path
    * @property string $created
    * @property string $updated
    * @property string $deleted
    */
    class Documents extends \yii\db\ActiveRecord
    {
         public $file;
         /**
          * @inheritdoc
         */
         public static function tableName()
         {
             return 'documents';
         }


         /**
          * @inheritdoc
         */
         public function rules()
         {
            return [
            [['doc_path'], 'required'],
            [['ref_id','doc_type'], 'integer'],
            [['deleted', 'heading', 'doc_type'], 'string'],
            [['file'],'safe'],
            [['file'],'file'],
            [['ref_id'], 'string', 'max' => 100],
            [['heading', 'doc_remarks'], 'string', 'max' => 1000],
            [['doc_path'], 'string', 'max' => 500],
            [['created', 'updated'], 'string', 'max' => 50],
            ];
         }

        /**
         * @inheritdoc
        */
         public function attributeLabels()
         {
             return [
            'id' => Yii::t('app', 'ID'),
            'ref_id' => Yii::t('app', 'Ref ID'),
            'heading' => Yii::t('app', 'Heading'),
            'doc_type' => Yii::t('app', 'Doc Type'),
            'doc_remarks' => Yii::t('app', 'Doc Remarks'),
            'doc_path' => Yii::t('app', 'Doc Path'),
            'created' => Yii::t('app', 'Created'),
            'updated' => Yii::t('app', 'Updated'),
            'deleted' => Yii::t('app', 'Deleted'),
            ];
         }
    }

这是我的观点，

 <?php

  use yii\helpers\Html;
  use yii\widgets\ActiveForm;


  /* @var $this yii\web\View */
  /* @var $model backend\models\Documents */
  /* @var $form yii\widgets\ActiveForm */
  ?>

  <div class="documents-form">
  <?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]); ?>
  <div class="panel panel-primary">
    <div class="panel-heading">
      <h2 class="panel-title">Compare Quotation</h2>
    </div>
  <div class="panel-body">
    <?= $form->field($model, 'ref_id')->textInput() ?>
    <?= $form->field($model, 'file')->fileInput(['class' => 'file', 'data- preview-file-type' => 'any', 'data-upload-url' => '#']) ?> 
    <?= Html::submitButton($model->isNewRecord ? Yii::t('app', 'Save') :   Yii::t('app', 'Update'), ['class' => $model->isNewRecord ? 'btn btn-success  pull-right' : 'btn btn-primary pull-right']) ?>
    </div>
    <?php ActiveForm::end(); ?>
  </div>

这是我的控制者，

use yii\web\UploadedFile;
 public function actionCreate()
 {
    $model = new Documents();

     //file upload
    $path = Yii::getAlias('@backend').'/web/';

    if ($model->load(Yii::$app->request->post())) {

        //variable which declare in model---file 
        $model->file = UploadedFile::getInstance($model, 'file');

        $save_file = '';

        if($model->file){

           $imagepath = 'docs/rec_quotations/'; // Create folder under web/images/logo
           //save into database
           $model->heading = $model->file;
           $model->doc_path = $imagepath.$model->file;

           $save_file = 1;
        }
        if ($model->save(false)) {
            if($save_file){
                $model->file->saveAs($path.$model->file);
            }
         }
        return $this->redirect(['view', 'id' => $model->id]);
    } else {
        return $this->render('create', [
            'model' => $model,
        ]);
    }

请帮帮我!!提前谢谢。