qt打开sqlite数据库文件后，怎么删除文件

    {        QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE","DB1");            db.setDatabaseName("tt.db3");        bool ok = db.open();        bool bLoad = db.isDriverAvailable("QSQLITE");        bool bOpen = db.isOpen();        bool berr = db.isOpenError();        QSqlQuery query(db);//"SELECT area FROM tbl_score");        query.exec("SELECT area FROM tbl_score");        while (query.next()) {            QString country = query.value(0).toString();            std::cout<<country.toStdString()<<std::endl;        }        db.close();    }    QSqlDatabase::removeDatabase("DB1");    QFile::remove("tt.db3");