[QT] create mycombobox click event

stay QT Medium ui Interface add QComboBox Control , The requirement is to implement the click event of the control , Checked the data , It is found that the control class itself has no click signal to use . Make ComboBox Click events can be divided into three steps ：

1、 rewrite ComboBox class ;

2、 stay widget Add the corresponding start signal and slot event ;

3、 stay ui Window will ComboBox Control is promoted to the overridden class ;

mycombobox.h

#ifndef MYCOMBOBOX_H
#define MYCOMBOBOX_H
#include <QComboBox>
#include <QMouseEvent>
class MyComboBox : public QComboBox
{
    Q_OBJECT// Only join Q_OBJECT, To use the signal signal Slot slot The mechanism of 
public:
    explicit MyComboBox(QWidget *parent = 0);
    ~MyComboBox();
protected:
    virtual void mousePressEvent(QMouseEvent *e);// Add mouse click events 
signals:
    void clicked();// Custom click signal , stay mousePressEvent Trigger when an event occurs 
};
#endif // MYCOMBOBOX_H

mycombobox.c

#include "mycombobox.h"
MyComboBox::MyComboBox(QWidget *parent) : QComboBox(parent)
{
}
MyComboBox::~MyComboBox()
{
}
// rewrite mousePressEvent event , Check whether the event type is left click 
void MyComboBox::mousePressEvent(QMouseEvent *e)
{
    if (e->button() == Qt::LeftButton)
    {
        emit clicked(); // Trigger clicked The signal 
    }
    QComboBox::mousePressEvent(e); // Pass the event to the parent class for processing , This sentence is very important , without , The parent class cannot handle the original click event 
}

mainwindow.h

public slots:
    void ComboBoxClicked();// Add slot function 

mainwindow.c

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // Add links , When you click send to ComboBoxClicked()
    connect(ui->cbb_pztWorkModel, SIGNAL(clicked()), this, SLOT(ComboBoxClicked()));
}

void MainWindow::ComboBoxClicked() {
    ui->statusbar->showMessage(" Please enter the correct even number Hex character （Hex Characters contain only 0~9、A~F、 Space ）", 2000);
}

About lineEdit The promotion steps of the control are , Click to enter the window ui Design interface —— Choose ComboBox Control —— Right click —— Upgrade to —— Add the newly rewritten class to the promoted class name MyComboBox, Then select —— promote ;