Cannot write simple text to a text file

[sammy742]

I am not able to write any text to my text files. When I go to 'File' > 'Open File or Project', I can see that 'txt1.txt' is in the same directory as main.cpp. These files are both in the 'startProgram' folder that contains the entire application. In 'startProgram.pro' it shows the following;

QT += core
QT -= gui
TARGET = startProgram
CONFIG += console
CONFIG -= app_bundle
TEMPLATE = app
SOURCES += main.cpp
OTHER_FILES +=
txt1.txt \

---

This works in eclipse, but not in QT:

@
#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
ofstream myfile;
myfile.open ("example.txt");
myfile << "Writing this to a file.\n";
myfile.close();
return 0;
@

This doesn't work in QT either:

@
#include <QtCore/QCoreApplication>
#include <QFile>
#include <QTextStream>

int main ()
{
QString filename="txt1.txt";
QFile file( filename );
QTextStream stream( &file );
stream << "something" << endl;

return 0;

}
@

Sincerely, sammy

[sierdzio]

You need to open the file before writing. See the documentation for QFile.
@
QFile file("txt1.txt");

if (file.open(QIODevice::Write | QIODevice::Text)) {
// now write using QTextStream or QByteArray
file.write("my text");
}

file.close(); // not needed, file is closed in constructor
@

[dbzhang800]

1. open the file before you can read/write it.

@
QFile::open()
@

2. Be careful when using relative paths, when not familiar with CWD.

[sammy742]

//

[sammy742]

@
#include <iostream>
#include <QCoreApplication>
#include <QFile>
#include <QTextStream>
using namespace std;

int main()
{

QFile file("C:/Qt/Qt5.0.2/Tools/QtCreator/bin/startProgram/txt1.txt";

if (file.open(QIODevice::WriteOnly | QIODevice::Text)) {

cout << "it works!!!" << endl;

// now write using QTextStream or QByteArray

QTextStream stream( &file );
file.write("my text\n");
stream << "Written text in Qt\n";}

return 0;
}
@

When I used 'QFile file("txt1.txt");' the console printed 'it works!!!' , but the txt1.txt file was not showing the written text. Everything worked correctly after entering the full path of the text file :
QFile file("C:/Qt/Qt5.0.2/Tools/QtCreator/bin/startProgram/txt1.txt");

[KA51O]

you forgot the QFile::close call.

Also please use "@" tags around your code to make it readable. This way you can easily spot all the mistakes you made in your code.
@
#include <iostream>
#include <QCoreApplication>
#include <QFile>
#include <QTextStream>
using namespace std;

int main()
{
// MISSING ")" closing bracket
QFile file(“C:/Qt/Qt5.0.2/Tools/QtCreator/bin/startProgram/txt1.txt”;
if (file.open(QIODevice::WriteOnly | QIODevice::Text))
{
cout << “it works!!!” << endl;
// now write using QTextStream or QByteArray QTextStream stream( &file );
file.write(“my text\n”);
stream << “Written text in Qt\n”;
}
// MISSING QFILE::CLOSE() CALL
return 0;
}
@

[sierdzio]

Please always wrap your code in '@' tags. Modifying your old posts will be a nice bonus, too :)

As 1+1=2 said: take care about relative paths, they can be misleading at times.