Copying the file content

jsulm

@suslucoder said in Copying the file content:

it returns nothing, Either true or false

?
It returns a boolean.
Again: what does it return?!

qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");

J.Hilk

@suslucoder then the function isn't called.

Please post what you actually have in your code, otherwise no-one will be able to help you

deleted286

@jsulm it returns false. Ekran görüntüsü 2021-01-11 111741.png

#include "mythread.h"
#include "mainwindow.h"
#include <QtCore>
#include <QDebug>
#include <QFile>
#include <QTimer>
#include <QThread>
#include <QMutex>
#include <QQueue>
#include <QMessageBox>
#include <QApplication>
#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QFileDialog>
#include <QMainWindow>

QFile file("C:/Users/ilknu/Documents/MyThread/deneme.txt");


MyThread::MyThread(QObject* parent)
    : QThread(parent)
{
    writeData();
}

MyThread::~MyThread()
{

}

void MyThread::writeData()
{
    QFile file2("C:/Users/ilknu/Documents/MyThread/new.txt");
    QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
    qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
    qDebug() << "im working in writing thread";

    emit writingDone();

}

void MyThread::run()  //Reading file from txt with thread1
{

    if (file.open(QIODevice::ReadOnly))
    {
        QTextStream in (&file);
        while (!in.atEnd())
        {
            QString line = in.readAll();
            QStringList list = line.split(QLatin1Char(' '), Qt::SkipEmptyParts);
            for(const QString &entry : list)
            {
                double num = entry.toDouble();
                queue.enqueue(num);

            }


            qDebug()<< "im running on worker thread " <<line;

        } // for
    } // while
    file.close();
} // if

sierdzio

Check if it exists:

qDebug() << "Source exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/deneme.txt");
qDebug() << "Destination exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/new.txt");

You need to check destination because:

If a file with the name newName already exists, copy() returns false (i.e., QFile will not overwrite it).

JonB

@suslucoder
Did you read the documentation of QFile::Copy() for yourself?

Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

So, does the destination file already exist? Does the source file also exist?

SGaist

Hi,

@suslucoder said in Copying the file content:

QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");

You do not have the same paths in the qDebug and the previous line.
You do realise that you are copying it twice ?

deleted286

@sierdzio
They exists.

Ekran görüntüsü 2021-01-11 112331.png

JonB

@SGaist , @sierdzio , @J-Hilk
If QFile::copy() returns false, I don't see anywhere the user can obtain any kind of error message/reason for the failure. Does Qt not supply this by any means?

deleted286

@SGaist I fixed it

JonB

@suslucoder said in Copying the file content:

They exists.

And? We have all said QFile::copy() says:

Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

So you (not we) need to do something about that.

Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls.

sierdzio

@suslucoder

Then the cause is clear: destination exists, so copy() will not overwrite it. You need to remove the destination file first, before calling copy().

deleted286

@JonB said in Copying the file content:

Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls. I've fixed it, it is my mistake.

Even i delete the destination file, for returning true by creating new destination, it returns false.

jsulm

@suslucoder Did you check what @SGaist said? Do NOT call copy twice! Call it once like before but put qDebug() in front of it...

deleted286

@sierdzio I'll try it again thank you

deleted286

@suslucoder it works. thank you