QFile / QTextStream

[ClaraCaste]

Hi everyone,

I want to do a very simple thing but I can't do it ...
I have a log file saved in some place (D://test.txt), I use a QTextStream to write text in it.

m_file.setFileName(fileName);
if (m_file.open(QIODevice::WriteOnly|QIODevice::Text))
{
	m_streamFile.setDevice(&m_file);
}

...

m_streamFile << msg;
endl(m_streamFile);

I create a menu to change its location.
I just replace the file name:

m_file.rename(dirName + "/" + fileName + ".txt");

But when new log messages appear, they are not written in the new file ...

Any idea ?

Thanks !

[VRonin]

before m_streamFile << msg; could you put Q_ASSERT(m_streamFile.device()->isOpen()); ?

[micland]

The API of QFile::rename(...) says:
"The file is closed before it is renamed."
So you have to open the file again after renaming...

[ClaraCaste]

@VRonin said:

Q_ASSERT(m_streamFile.device()->isOpen());

You are right, the file is closed. But if I open it, the previous file content is cleared ...

m_file.rename(newFileName);
if (m_file.open(QIODevice::WriteOnly | QIODevice::Text))
{
	m_streamFile.setDevice(&m_file);
}

[micland]

@ClaraCaste Try to open in append mode, otherwise the file will be truncated:
if (m_file.open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Append))

[ClaraCaste]

It works !
It seems obvious ...
Thank you very much !