$form->field($model, ‘username‘)->dropDownList(ArrayHelper::map($data,‘id‘, ‘customer_name‘));
方法2
Html::activeDropDownList($model, ‘username‘, ArrayHelper::map($data,‘id‘, ‘customer_name‘), [‘style‘ => ‘border:1px solid red;‘]);
方法3
Html::dropDownList(‘username‘, null, ArrayHelper::map($data,‘id‘, ‘customer_name‘), [‘class‘ => ‘dropdownlist‘]);
原文：http://www.cnblogs.com/liadmin/p/6360836.html