<?= GridView::widget([
   'dataProvider' => $dataProvider,
   'showFooter' => true, //设置显示最下面的footer
    'id' => 'grid',
    'columns' => [
     [
      'class'=>CheckboxColumn::className(),
      'name'=>'id',
      'headerOptions' => ['width'=>'30'],
      'footer' => '<button href="#" rel="external nofollow" class="btn btn-default btn-xs btn-delete" url="'. Url::toRoute('admin/delete') .'">删除</button>',
      'footerOptions' => ['colspan' => 5],
     ],
     ['attribute' => 'id', 'footerOptions' => ['class'=>'hide']], //其他列每个都要增加footerOptions项，设置class为hide，到达隐藏效果；
     ['attribute' => 'username', 'footerOptions' => ['class'=>'hide']],
     [
      'attribute' => 'status',
      'value' => function($model){
       if ($model->status == Admin::STATUS_ACTIVE){
        return '启用';
       }
       return '禁用';
      },
      'footerOptions' => ['class'=>'hide']
     ],
     ['class' => 'yii\grid\ActionColumn', 'header' => '管理操作', 'footerOptions' => ['class'=>'hide']],
    ],
   'layout' => "{items}\n{pager}"
  ]); ?>

var ids = $("#grid").yiiGridView("getSelectedRows");