KeyPressEvent onyl works after button is clicked.

Ucn_

KeyPressEvent only works after button is clicked, is it supposed to work that way? Or I did some mistakes in the code, the code:

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QObject>
#include <QWidget>
#include <QtWidgets>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:

    Ui::MainWindow *ui;
};

class keyEnterReceiver : public QObject
{
    Q_OBJECT
public:
  keyEnterReceiver(QWidget *parent = 0);


protected:
    bool eventFilter(QObject* obj, QEvent* event);
};
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QKeyEvent>
#include <QDebug>

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

    keyEnterReceiver* key = new keyEnterReceiver();
    ui->pushButton_2->installEventFilter(key);


}

MainWindow::~MainWindow()
{
    delete ui;
}

keyEnterReceiver::keyEnterReceiver(QWidget *parent)
    : QObject(parent)
{

}


bool keyEnterReceiver::eventFilter(QObject* obj, QEvent* event)
{
    if (event->type()==QEvent::KeyPress) {
        QKeyEvent* key = static_cast<QKeyEvent*>(event);
        if ( (key->key()==Qt::Key_B) || (key->key()==Qt::Key_C) ) {
            
            qDebug() << "The keys were pressed" << key;
        } else {
            return QObject::eventFilter(obj, event);
        }
        return true;
    } else {
        return QObject::eventFilter(obj, event);
    }
    return false;
}

mainwindow.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="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>10</x>
      <y>30</y>
      <width>91</width>
      <height>41</height>
     </rect>
    </property>
    <property name="text">
     <string>PushButton</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton_2">
    <property name="geometry">
     <rect>
      <x>10</x>
      <y>80</y>
      <width>91</width>
      <height>41</height>
     </rect>
    </property>
    <property name="text">
     <string>PushButton</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

Thanks

mrjj

Hi
A widget only receives keyboard events if it has the focus.
So clicking the button first will focus it and then it will get keys.

So yes its working as intended :)

Ucn_

@mrjj Thanks, I solved by setting the focus ... ui->pushButton_2->setFocus();