yii的csv导出

public static function export($parameter){
        if (is_array($parameter)) {
            $filename = date(‘Y-m-d_H-i-s‘) . ‘.csv‘;        
            header(‘Content-Type: text/csv‘);
            header("Content-Disposition: attachment;filename={$filename}");
            $fp = fopen(‘php://output‘, ‘w‘);
            fwrite($fp,chr(0xEF).chr(0xBB).chr(0xBF));
            if ( ! empty($parameter[‘header‘]) && is_array($parameter[‘header‘])) {
                fputcsv($fp, $parameter[‘header‘]);
            }
            if (isset($parameter[‘data‘])) {
                foreach ($parameter[‘data‘] as $row) {
                    fputcsv($fp, $row);
                }
            }return true;
        }
        throw new \yii\web\HttpException(500, "Not a valid parameter!");
  }