In this tutorial we will learn How to use signal and slots in qt.
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We keep the class as MainWindow as given by default.
SignalsAndSlots.pro
#------------------------------------------------- # # Project created by QtCreator 2016-04-13T22:32:27 # #------------------------------------------------- QT += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TARGET = SignalsAndSlots TEMPLATE = app SOURCES += main.cpp\ mainwindow.cpp HEADERS += mainwindow.h FORMS += mainwindow.ui
mainwindow.h
#ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> namespace Ui { class MainWindow; } class MainWindow : public QMainWindow { Q_OBJECT public: explicit MainWindow(QWidget *parent = 0); ~MainWindow(); private: Ui::MainWindow *ui; }; #endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); connect(ui->horizontalSlider,SIGNAL(valueChanged(int)), ui->progressBar,SLOT(setValue(int))); disconnect(ui->horizontalSlider,SIGNAL(valueChanged(int)), ui->progressBar,SLOT(setValue(int))); } MainWindow::~MainWindow() { delete ui; }
main.cpp
#include "mainwindow.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); MainWindow w; w.show(); return a.exec(); }
Sir, can u provide me the code or tutorial for making a drag and droppable QtextEdit in QT, which can also be resized manually by the user according to his/her need. I searched it many times but couldn’t find it.
why the disconnect right after the connect??