Copying the file content

jsulm

@suslucoder said in Copying the fle content:

It does not copy the file

That I already understood.
Again: what does QFile::copy return?

I also do not understand what how this file copy is related to the other code:

if(!file.open(QIODevice::ReadOnly)) // What is file here? What file are you trying to pen here?

sierdzio

@suslucoder said in Copying the fle content:

qDebug does not give anytghing on the secreen

This means that MyThread::writeData() function is not called at all! And that implies the problem lies somewhere else (not in QFile::copy()).

deleted286

@sierdzio I've already called it with start() function. Doesnt it started the thread?

sierdzio

Yes, start() starts the thread, but it does not mean your writeData() is called. If that were true, you would see your qDebug() output, because it is not in any if conditions - it should be printed every time writeData() is called.

deleted286

@sierdzio yes you are right. I've called the function. Thread is working now. But copying issue does not work.

sierdzio

I don't know either, you have not shown any code or stated how you want it all to work... so all I can say is "read the docs" :D QThread has a nice example and detailed description: https://doc.qt.io/qt-5/qthread.html#details

deleted286

@sierdzio I just want, when writeData() thread is called, copy the contents into new txt.

J.Hilk

@suslucoder
QThread has a started signal you connect that signal to your slot

deleted286

@J-Hilk My thread has working now. But copying does not occur

jsulm

@suslucoder So, what does copy() return?

deleted286

@jsulm it returns nothing, Either true or false

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