Qt/Widgets/ComboBox

demo.cpp

#include <QApplication>
 
#include "main.h"
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow window;
    window.show();
    return app.exec();
}

main.cpp

#include <QtGui>
#include <iostream>
 
#include "main.h"
 
MainWindow::MainWindow(QMainWindow* parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);
    connect( this->ui.comboBox, SIGNAL( activated(int) ), this, SLOT(comboBox_Activated()) );
}
 
void MainWindow::comboBox_Activated()
{
  std::cout << "Activated " << this->ui.comboBox->currentIndex() << std::endl;
}

main.h

#ifndef CALCULATORFORM_H
#define CALCULATORFORM_H
 
#include <QMainWindow>
 
#include "ui_main.h"
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    MainWindow(QMainWindow *parent = 0);
 
public slots:
 
    void comboBox_Activated();
 
private:
    Ui::MainWindow ui;
};
 
#endif

main.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QComboBox" name="comboBox">
    <property name="geometry">
     <rect>
      <x>240</x>
      <y>150</y>
      <width>211</width>
      <height>27</height>
     </rect>
    </property>
    <item>
     <property name="text">
      <string>Item1</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>Item2</string>
     </property>
    </item>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>25</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

CMakeLists.txt

cmake_minimum_required(VERSION 2.6)
 
PROJECT(ComboBox)
 
FIND_PACKAGE(Qt4 REQUIRED)
INCLUDE(${QT_USE_FILE})
 
include_directories(${include_directories} ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})
 
QT4_WRAP_UI(UISrcs main.ui)
QT4_WRAP_CPP(MOCSrcs main.h)
 
ADD_EXECUTABLE(ComboBox demo.cpp main.h main.cpp ${MOCSrcs} ${UISrcs})
TARGET_LINK_LIBRARIES(ComboBox ${QT_LIBRARIES})