lib/components/web/widgets/grid/View.php
public function getColumns()
    {
        if (is_null($this->_columns)) {
            $this->columns = $this->dataProvider->model->attributeNames();
        }

        return $this->_columns;
    }
public function getColumns()
    {
        if (is_null($this->_columns)) {
            $this->columns = $this->dataProvider->model->attributeNames();
        }

        return $this->_columns;
    }
Get columns.

@return [[@doctodo return_type:getColumns]] [[@doctodo return_description:getColumns]]