qt 文件的写入与读出

QString ss = ui -> textEdit -> toPlainText ();

        ui->textBrowser->append(ss);

        ui->textEdit->clear();

        QFile file(str1);

        if(!file.open(QIODevice::WriteOnly))

        {

            QMessageBox::warning(this,tr("Warning"),tr("file wrong"),QMessageBox::Yes);

        }

        QTextStream out(&file);

        out<<ss;

        file.close();

}

 QFile file("qt2");

        if(!file.open(QIODevice::ReadOnly))

        {

            QMessageBox::warning(this,tr("Warning"),tr("file wrong"),QMessageBox::Yes);

        }

        QTextStream in(&file);

        while(!in.atEnd())

        {

         QString line=in.readAll();

         ui->textBrowser->append("qt2");

         ui->textBrowser->append(line);

        }

        file.close();