Qt 5.5-触摸屏事件仅在初始（第一个）窗口中有效

Question

I've set up a basic Qt-Widgets-Application (Qt 5.5 community) with a simple QWidget "MainWindow" and an additinal QWidget "SettingsScreen".

Within the "MainWindow", touchscreen-events (handled by OS) are working as expected, but after opening the "SettingsScreen" all touch-events are executed on the desktop until I close the "SettingsScreen" using mouse or keyboard.

Environment:

• Ubuntu Studio 14.04.03
• Qt 5.5 Open Source Edition

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QWidget>
#include <settingsscreen.h>

namespace Ui {
class MainWindow;
}

class MainWindow : public QWidget
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:

    void on_btnExit_clicked();

    void on_btnSettings_clicked();

private:
    Ui::MainWindow *ui;
    SettingsScreen *wSettingsScreen;
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "settingsscreen.h"
#include "ui_settingsscreen.h"

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

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

void MainWindow::on_btnExit_clicked()
{
    this->close();
}

void MainWindow::on_btnSettings_clicked()
{
    wSettingsScreen = new SettingsScreen(parentWidget());
    wSettingsScreen->show();
}

settingsscreen.h

#ifndef SETTINGSSCREEN_H
#define SETTINGSSCREEN_H

#include <QWidget>

namespace Ui {
class SettingsScreen;
}

class SettingsScreen : public QWidget
{
    Q_OBJECT

public:
    explicit SettingsScreen(QWidget *parent = 0);
    ~SettingsScreen();

private slots:
    void on_pushButton_clicked();

    void on_btnBack_clicked();

private:
    Ui::SettingsScreen *ui;
};

#endif // SETTINGSSCREEN_H

settingsscreen.cpp

#include "settingsscreen.h"
#include "ui_settingsscreen.h"

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

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

void SettingsScreen::on_btnBack_clicked()
{
    this->close();
}

I've just started developing with Qt, so please forgive me if I'm missing something essential :)

Any help would by highly appreciated!!

Thank you in advance!

Answer 1

Actually the thing is QMainwindow or any base Widget of your application is able to properly synthesize the Unhandled touch screen events to Mouse events. So whenever you are creating a dialog/widget, make sure to set Mainwindow as there parent and in the constructor of the child widget use setParent(parent). Even I was facing this kind of Issue and this worked for me.