Big problem in reading&writing binary files

sajastu

hi,
i have a big problem in qt, assume that i use binary files and write data to them.
my data are strings,
and i want them string (in output mode) whenever i read them.
any help will be appreciated :)
thanks in advance.

Jeroentjehome

Hi,
On your QFile pointer you could set a QByteArray and check out that class to define how do you need that data from the file. The fromHex en toHex jump to mind in your case.
Greetz

sajastu

Thanks for your reply,
look, this is my code :

for writing:
[code]

QString strToWrite = ui->User_signUp->text()+ui->Pass_signUp->text();
QFile fileToWrite("users.dat");
QDataStream dataStreamWriter(&fileToWrite);
fileToWrite.open(QIODevice::WriteOnly);
dataStreamWriter << strToWrite;
fileToWrite.close();

[/code]

and for reading:

[code]
QString strToRead= "";
QFile fileToRead("users.dat");
QDataStream dataStreamReader(&fileToRead);
fileToRead.open(QIODevice::ReadOnly);
dataStreamReader >> strToRead;
fileToRead.close();

    qDebug() << strToRead;

[/code]

but in this case problem is that qDebug does'nt work.

SGaist

Hi and welcome to devnet,

Is it a typo or are you really writing to users.bin and reading from file.bin ?

sajastu

Sorry i change the code with QByteArray,

for writing:

[code]

QByteArray ar=ui->User_signUp->text().toUtf8()+"%"+ ui->Pass_singUp->text().toUtf8()+"$";
QFile file("users.dat");
file.open(QIODevice::WriteOnly | QIODevice::Append );
file.write(ar);

[/code]

this code writes the usernames and passwords correctly

Now assume that i want to search a specified String(username) in my file, I think i can do this by using 2 QByteArrays, one for the username (which user has entered) and another for the file which reads whole file.
but i don't know how i can use them. could you help me?

SGaist

Are you thinking about QByteArray::contains ?