Saving text to a file when a QPushbutton is pressed - c++

Question

I have been login for a way to save some text to a file when I press a QPushbutton and I was wondering if anyone could lead me to somewhere to find out?
I am programing in qt 5.12 with C++.

Answer 1

You can try the following code:
.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPushButton>
#include <QFile>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
QPushButton *button = new QPushButton(this);
button->setText("Push Here");
button->setGeometry(0, 0, 100, 30);
button->show();
//signal and slot connection
connect(button, &QPushButton::clicked, this, &MainWindow::writeSomeText);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::writeSomeText()
{
QFile n_file("file.txt");
if(n_file.open(QIODevice::WriteOnly)) //open a file
{
n_file.write("Some Text"); // write on a file
n_file.close(); //close the file
}
}
.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
public slots:
void writeSomeText();
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
Please be sure to check Signal And Slot doc and QFile Class to better understanding of the code.

Answer 2

use a QFile and a QTextStream, open the file with readWrite flags stream the text whenever you need
void MainWindow::on_Button_clicked()
{
QString filename{"MyFile.txt"};
QFile file{filename};
if(file.open(QIODevice::ReadWrite | QIODevice::Truncate | QIODevice::Text))
{
QTextStream stream(&file);
stream << "Hello World" << endl;
file.close();
}
}