QFile and Creating Files

[Jingoism]

Ok first off I am a total noob at C++ and QT as I just started a few days ago, but I have been trudging through some online tutorials and just recently hit a snag. I am quite sure it's a simple issue, but here goes.

Got a list widget, line edit widget and a button that when pressed outputs the text to the list widget and then outputs to a file. Now I got it working great as long as I hard coded the filename into my program, but when I wanted to possibly create a new file I could not figure out where to put it.

You can see below where I wanted to put it, but I knew it would not work since it was encapsulated by the if statement. I think my brain is fried from looking at all this for too long hehe.

void DialogImpl::doSomething() {
	QString linedt = lineEdit->text(); // Set linedt to the text in the Line Edit box
	if (!file.isOpen()) && ( linedt != "" ) { // If file is not open then open it
		QFile file("/home/jingoism/" + linedt); // This is wrong, and the part I dont understand
		QTextStream out(&file); // Also wrong, should go with QFile
		file.open(QIODevice::WriteOnly | QIODevice::Text); // Open the file as Writeonly
		listWidget->addItem("Opened File!"); // Verify in listWidget file is opened
		listWidget->addItem(linedt); // Add the line of text to the listWidget
		out << linedt << endl; // Add the line to the file
		lineEdit->clear(); // Clear the LineEdit box
	} else {
		if ( linedt != "" ) { // If text in the Line Edit box is not null then proceed
		out << linedt << endl;
		listWidget->addItem(linedt);
		lineEdit->clear();
		}
	}
}

void DialogImpl::doSomething() {
	QString linedt = lineEdit->text(); // Set linedt to the text in the Line Edit box
	if (!file.isOpen()) && ( linedt != "" ) { // If file is not open then open it
		QFile file("/home/jingoism/" + linedt); // This is wrong, and the part I dont understand
		QTextStream out(&file); // Also wrong, should go with QFile
		file.open(QIODevice::WriteOnly | QIODevice::Text); // Open the file as Writeonly
		listWidget->addItem("Opened File!"); // Verify in listWidget file is opened
		listWidget->addItem(linedt); // Add the line of text to the listWidget
		out << linedt << endl; // Add the line to the file
		lineEdit->clear(); // Clear the LineEdit box
	} else {
		if ( linedt != "" ) { // If text in the Line Edit box is not null then proceed
		out << linedt << endl;
		listWidget->addItem(linedt);
		lineEdit->clear();
		}
	}
}

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[marcel]

Hey, is this compiling at all?
You got it all wrong and you are right with some things .
You can do without QTextStream
QFile inherits QIODevice which has lower level methods for reading/writing files.

Your logic in writing this program is not correct.

void DialogIml::DialogImpl(...)
{
  mFile = new QFile(somePath); //sice you require constatnt access to the file, it should  be a member in your class.
  mFile->open(QIODevice::WriteOnly); //this should create the file if it does not exist
  //be careful because that could return false - if you lack permissions,etc
}
 
void DialogImpl::~DialogImpl()
{
 if(mFile)
  {
    mFile->close();
    delete mFile;
  }
}
 
void DialogImpl::DoSomething() 
{
  QString linedt = lineEdit->text();
  if(mFile->isOpen())
  {
    mFile->write(linedt.ascii());//Writes a QByteArray to the file.
  }
}

void DialogIml::DialogImpl(...)
{
  mFile = new QFile(somePath); //sice you require constatnt access to the file, it should  be a member in your class.
  mFile->open(QIODevice::WriteOnly); //this should create the file if it does not exist
  //be careful because that could return false - if you lack permissions,etc
}

void DialogImpl::~DialogImpl()
{
 if(mFile)
  {
    mFile->close();
    delete mFile;
  }
}

void DialogImpl::DoSomething() 
{
  QString linedt = lineEdit->text();
  if(mFile->isOpen())
  {
    mFile->write(linedt.ascii());//Writes a QByteArray to the file.
  }
}

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Should be more or less like this.

Regards

[Jingoism]

Ahh thats exactly what I was looking for. I knew the answer was probably fairly simple, but I could not seem to grasp how I would obtain constant access to the file. Of course now it seems really simple and I feel like a tool... hehe.

Thank you for the quick response though as I am thoroughly enjoying QT.