yii2 gridview 中 filter设置带搜索的下拉框[转载]

原文地址：

https://stackoverflow.com/questions/36937615/kartik-select2-as-filter-input-in-yii2-grid

代码如下：
引入select2插件:

use kartik\select2\Select2;

具体代码:

        ['attribute' => 'bank_id',
                'value' => function ($model) {
                    return $model->bank->bank_name;
                },
                'contentOptions' => [
                    'align' => 'center',
                ],
            'filter'=>Select2::widget(['name' => 'ApplyDepositRecordSearch[bank_id]',
                'data' => \livan\distribution\models\ars\ApplyDepositRecord::bankData(),
                'value' =>$searchModel->bank_id,
                'options' => ['placeholder' => '请选择开户行']
            ])
        ],