QT read/write text file from QLine Edit when Click QPushButton

[TheCeylann]

I need to write new password to text file and read from text file How Can I do that?

void SecondWindow::on_pushButton_8_clicked()
{

  

\\I  need read old password  from password.txt and write new one to text file


    }

void MainWindow::on_userLoginBtn_clicked()
{
\ I need read text fıle here
QString username = ui->usernameBox->text();
QString password = ui->passwordBox->text();

if (username == "test"   && password ==  "test"  ) {
    QMessageBox::information(this, "Giriş","Giriş Başarılı" );
    hide();
    secondWindow = new SecondWindow(this);
    secondWindow ->show();
}

}

How Can I do that. I m just started 2 days ago to qt and C++. Sorry for my information less.

[jsulm]

@TheCeylann Use https://doc.qt.io/qt-5/qfile.html to read/write files.
Keep in mind - storing passwords unencrypted is dangerous!

[Pl45m4]

Consider using QCryprographicHash, store the hash in your file and compare the hashes when the user enters a password.

• https://doc.qt.io/qt-5/qcryptographichash.html

@TheCeylann said in QT read/write text file from QLine Edit when Click QPushButton:

hide();
secondWindow = new SecondWindow(this);
secondWindow ->show();

Also, this might crash or exit your app since you hide the last visible widget/window.

• https://doc.qt.io/qt-5/qguiapplication.html#quitOnLastWindowClosed-prop