get selected column in gridview

hello , I have a problem in getting the selected row using kartik grid view. Here is my code :

[size="6"]the view:[/size]


<?= GridView::widget([

    'dataProvider'=> $dataProvider,

    'filterModel' => $searchInstance,

		'containerOptions' => ['class' => 'instance-pjax-container'],

		

		

		'export' => false,

    'columns' => [

            ['class' => 'yii\grid\SerialColumn'],


            'codebien',

		    'designationbien',

            'codesousfamille',

            'numfacture',

            'dt',

		    ['class' => 'yii\grid\CheckboxColumn'],


            ['class' => 'yii\grid\ActionColumn'],

        ],

    

    

]);?>




  <?= Html::SubmitButton( 'Affecter', [ 'class' => 'btn btn-success' , 'id' =>'x']) ?>    




  


  

  

  

  <?php

$script = <<< JS

$(function () {

		 $('#x').click(function(){

		

		 	$.post(

    "listeaffecter", 

    {

        pk : $('#instance-pjax-container').yiiGridView('getSelectedRows')

    },

    function () {

        $.pjax.reload({container:'#instance-pjax-container'});

    }

);

		

		 });

		

  });


JS;

$this->registerJs($script);

?>

  

[size="6"]the controller : [/size]


public function actionListeaffecter(){

    	 			

    	 			$searchInstance = new InstanceSearch();

    	 			$dataProvider = $searchInstance->search(Yii::$app->request->queryParams);

    	 			$pk = Yii::$app->request->post('pk'); // Array or selected records primary keys

    	 			if ($pk) {

    	 				print ("select=$pk");

    	 			}    	

    	 			    	 				

    	 			     return $this->render('vueListeAaffecter', [

    	 					'searchInstance' => $searchInstance,

    	 					'dataProvider' => $dataProvider,

    	 					]);

    	 			

    	 		}

Any help plz

It’s not necessary for me to use pjax. I put it because I found it in a forum. My aim is to get the selected rows