1  void MainWindow::on_saveButton_clicked()
2  {
3    QFile  outFile("file1.txt");
4    if(!outFile.open(QIODevice::Append |QIODevice::WriteOnly | QIODevice::Text)) {
5      QMessageBox::information(this, "Warning","File not open");
6      return;
7    }
8    QTextStream st (&outFile);
9    st << ui->lineEdit->text() + "\n";
10   ui->lineEdit->setText("");
11 }