How can I use a simple Dropdown list in the search box of GridView::widget, Yii2?
Add this in Gridview columns array:
[ 'attribute' => 'attribute_name', 'value' => 'attribute_value', 'filter' => Html::activeDropDownList($searchModel, 'attribute_name', ArrayHelper::map(ModelName::find()->asArray()->all(), 'ID', 'Name'),['class'=>'form-control','prompt' => 'Select Category']),],Change values according to your attributes.
You can also use below code
[ 'attribute'=>'attribute name', 'filter'=>array("ID1"=>"Name1","ID2"=>"Name2"),],OR
[ 'attribute'=>'attribute name', 'filter'=>ArrayHelper::map(Model::find()->asArray()->all(), 'ID', 'Name'),],