Qt designer and C++

[frankwas]

Hi all.

Can someone please help me. I have designed a GUI in Qt and have got my main.cpp code to execute the GUI and I have also been able to access my components via my C++ code, like changing button font size, etc. But one thing that I'm really struggeling with is to call one of my own functions from a button click. I have read about signals and slot, but I have not successfully connected the GUI's signals to my code. Can anyone please help me or point me to a site that hav a tutorial or code snippets so that I can understand how to implement this?

Thanks!

[Anthro]

Use MFC AppWizard, name your button, make it dialog based...
Place a button control on the dialog and double click on it to create its click event. Before typing the code for the button click (BN_CLICKED) event you must define a new function pointer with the correct number of parameters, according to the parameters of the function above.

[Judas]

The signal/slots mechanism is a core feature of Qt, it's documented in the offical docs at http://doc.trolltech.com/

Basically, you can define a local slot called <i>clickHandler()</i> like this in the your header file:

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private slots:
       void clickHandler ();

Then, in your implementation, you can connect the button's <i>clicked()</i> signal to your local slot like this:

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connect ( button, SIGNAL ( clicked() ), this, SLOT ( clickHandler() ) );

(Where <i>button</i> is a pointer to your button.)

Now every time the button is clicked your clickHandler() function will be called.

[frankwas]

Thanks a lot guys!


I'm gonna get cracking right away! I really appreciate your input!

Frank

[frankwas]

Ok, i'm really struggeling to get this working. This is my code. Could you please tell me where I need to put the "private slots" part in cause I get a compile error when I put it my header file. Also, I have a mainwindow.cpp and a main.cpp file. Where should i call/implement the function?

main.cpp:

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#include <QApplication>
#include <QPushButton>
#include <QFont>
#include "mainwindow.h"

int main(int argc,char** argv)
{
  QApplication app(argc,argv);
  MainWindow mw;
  
  
  mw.show();
  return app.exec();
}

mainwindow.cpp:

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#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
  : QMainWindow(parent)
{
  ui.setupUi(this);
  //ui.add_btn->
  connect(ui.add_btn, SIGNAL(clicked()), this, SLOT(clickHandler()));
}

mainwindow.h:

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#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "ui_mainform.h"

class MainWindow : public QMainWindow
{
  Q_OBJECT
  public:
    MainWindow(QWidget *parent = 0);
  
  private:
    Ui::MainWindow ui;
};

#endif