Yii2 ActiveDataProvider - Invalid argument supplied for foreach()

Array
(
    [0] => common\models\GoodsType Object
        (
            [children] => Array
                (
                    [0] => common\models\GoodsType Object
                        (
                            [children] => 
                            [_attributes:yii\db\BaseActiveRecord:private] => Array
                                (
                                    [id] => 3
                                    [name] => 新的笔记本
                                    [pid] => 1
                                    [sort] => 1
                                    [created_at] => 1574423302
                                    [updated_at] => 1574423302
                                )

                            [_oldAttributes:yii\db\BaseActiveRecord:private] => Array
                                (
                                    [id] => 3
                                    [name] => 新的笔记本
                                    [pid] => 1
                                    [sort] => 1
                                    [created_at] => 1574423302
                                    [updated_at] => 1574423302
                                )

                            [_related:yii\db\BaseActiveRecord:private] => Array
                                (
                                )

                            [_relationsDependencies:yii\db\BaseActiveRecord:private] => Array
                                (
                                )

                            [_errors:yii\base\Model:private] => 
                            [_validators:yii\base\Model:private] => 
                            [_scenario:yii\base\Model:private] => default
                            [_events:yii\base\Component:private] => Array
                                (
                                    [beforeInsert] => Array
                                        (
                                            [0] => Array
                                                (
                                                    [0] => Array
                                                        (
                                                            [0] => yii\behaviors\TimestampBehavior Object
                                                                (
                                                                    [createdAtAttribute] => created_at
                                                                    [updatedAtAttribute] => updated_at
                                                                    [value] => 
                                                                    [attributes] => Array
                                                                        (
                                                                            [beforeInsert] => Array
                                                                                (
                                                                                    [0] => created_at
                                                                                    [1] => updated_at
                                                                                )

                                                                            [beforeUpdate] => updated_at
                                                                        )

                                                                    [skipUpdateOnClean] => 1
                                                                    [preserveNonEmptyValues] => 
                                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                                )

                                                            [1] => evaluateAttributes
                                                        )

                                                    [1] => 
                                                )

                                        )

                                    [beforeUpdate] => Array
                                        (
                                            [0] => Array
                                                (
                                                    [0] => Array
                                                        (
                                                            [0] => yii\behaviors\TimestampBehavior Object
                                                                (
                                                                    [createdAtAttribute] => created_at
                                                                    [updatedAtAttribute] => updated_at
                                                                    [value] => 
                                                                    [attributes] => Array
                                                                        (
                                                                            [beforeInsert] => Array
                                                                                (
                                                                                    [0] => created_at
                                                                                    [1] => updated_at
                                                                                )

                                                                            [beforeUpdate] => updated_at
                                                                        )

                                                                    [skipUpdateOnClean] => 1
                                                                    [preserveNonEmptyValues] => 
                                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                                )

                                                            [1] => evaluateAttributes
                                                        )

                                                    [1] => 
                                                )

                                        )

                                )

                            [_eventWildcards:yii\base\Component:private] => Array
                                (
                                )

                            [_behaviors:yii\base\Component:private] => Array
                                (
                                    [0] => yii\behaviors\TimestampBehavior Object
                                        (
                                            [createdAtAttribute] => created_at
                                            [updatedAtAttribute] => updated_at
                                            [value] => 
                                            [attributes] => Array
                                                (
                                                    [beforeInsert] => Array
                                                        (
                                                            [0] => created_at
                                                            [1] => updated_at
                                                        )

                                                    [beforeUpdate] => updated_at
                                                )

                                            [skipUpdateOnClean] => 1
                                            [preserveNonEmptyValues] => 
                                            [owner] => common\models\GoodsType Object
 *RECURSION*
                                        )

                                )

                        )

                )

            [_attributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 1
                    [name] => 办公新来的
                    [pid] => 0
                    [sort] => 0
                    [created_at] => 1574423302
                    [updated_at] => 1574423302
                )

            [_oldAttributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 1
                    [name] => 办公新来的
                    [pid] => 0
                    [sort] => 0
                    [created_at] => 1574423302
                    [updated_at] => 1574423302
                )

            [_related:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_relationsDependencies:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_errors:yii\base\Model:private] => 
            [_validators:yii\base\Model:private] => 
            [_scenario:yii\base\Model:private] => default
            [_events:yii\base\Component:private] => Array
                (
                    [beforeInsert] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                    [beforeUpdate] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                )

            [_eventWildcards:yii\base\Component:private] => Array
                (
                )

            [_behaviors:yii\base\Component:private] => Array
                (
                    [0] => yii\behaviors\TimestampBehavior Object
                        (
                            [createdAtAttribute] => created_at
                            [updatedAtAttribute] => updated_at
                            [value] => 
                            [attributes] => Array
                                (
                                    [beforeInsert] => Array
                                        (
                                            [0] => created_at
                                            [1] => updated_at
                                        )

                                    [beforeUpdate] => updated_at
                                )

                            [skipUpdateOnClean] => 1
                            [preserveNonEmptyValues] => 
                            [owner] => common\models\GoodsType Object
 *RECURSION*
                        )

                )

        ),
    [2] => common\models\GoodsType Object
        (
            [children] => Array
                (
                )

            [_attributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 4
                    [name] => 新的screen-shot
                    [pid] => 0
                    [sort] => 0
                    [created_at] => 1574423302
                    [updated_at] => 1574423302
                )

            [_oldAttributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 4
                    [name] => 新的screen-shot
                    [pid] => 0
                    [sort] => 0
                    [created_at] => 1574423302
                    [updated_at] => 1574423302
                )

            [_related:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_relationsDependencies:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_errors:yii\base\Model:private] => 
            [_validators:yii\base\Model:private] => 
            [_scenario:yii\base\Model:private] => default
            [_events:yii\base\Component:private] => Array
                (
                    [beforeInsert] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                    [beforeUpdate] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                )

            [_eventWildcards:yii\base\Component:private] => Array
                (
                )

            [_behaviors:yii\base\Component:private] => Array
                (
                    [0] => yii\behaviors\TimestampBehavior Object
                        (
                            [createdAtAttribute] => created_at
                            [updatedAtAttribute] => updated_at
                            [value] => 
                            [attributes] => Array
                                (
                                    [beforeInsert] => Array
                                        (
                                            [0] => created_at
                                            [1] => updated_at
                                        )

                                    [beforeUpdate] => updated_at
                                )

                            [skipUpdateOnClean] => 1
                            [preserveNonEmptyValues] => 
                            [owner] => common\models\GoodsType Object
 *RECURSION*
                        )

                )

        )

    [3] => common\models\GoodsType Object
        (
            [children] => Array
                (
                )

            [_attributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 5
                    [name] => 办公用品
                    [pid] => 0
                    [sort] => 
                    [created_at] => 1574647082
                    [updated_at] => 1574647082
                )

            [_oldAttributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 5
                    [name] => 办公用品
                    [pid] => 0
                    [sort] => 
                    [created_at] => 1574647082
                    [updated_at] => 1574647082
                )

            [_related:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_relationsDependencies:yii\db\BaseActiveRecord:private] => Array
                (
                )

            [_errors:yii\base\Model:private] => 
            [_validators:yii\base\Model:private] => 
            [_scenario:yii\base\Model:private] => default
            [_events:yii\base\Component:private] => Array
                (
                    [beforeInsert] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                    [beforeUpdate] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [skipUpdateOnClean] => 1
                                                    [preserveNonEmptyValues] => 
                                                    [owner] => common\models\GoodsType Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                )

            [_eventWildcards:yii\base\Component:private] => Array
                (
                )

            [_behaviors:yii\base\Component:private] => Array
                (
                    [0] => yii\behaviors\TimestampBehavior Object
                        (
                            [createdAtAttribute] => created_at
                            [updatedAtAttribute] => updated_at
                            [value] => 
                            [attributes] => Array
                                (
                                    [beforeInsert] => Array
                                        (
                                            [0] => created_at
                                            [1] => updated_at
                                        )

                                    [beforeUpdate] => updated_at
                                )

                            [skipUpdateOnClean] => 1
                            [preserveNonEmptyValues] => 
                            [owner] => common\models\GoodsType Object
 *RECURSION*
                        )

                )

        )
)