Welcome, I have a question about Qt's windows operations. I have a simple app which contains 2 windows:
MainWindow - includes push button, can't be resizeable,
AdminWindow - includes label, can be resizeable.
When I click push button, it should open AdminWindow and hide MainWindow. I made the app and it seems to work but when I open the AdminWindow, the application icon which is located in windows's bottom bar is missing. How can I fix it?
Icon is showed when MainWindow is opened:
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "adminwindow.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_pushButtonOpenAdmin_clicked();
private:
Ui::MainWindow *ui;
AdminWindow *adminWindow;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
// hides MainWindow and show AdminWindow
void MainWindow::on_pushButtonOpenAdmin_clicked()
{
hide();
adminWindow = new AdminWindow(this);
adminWindow->show();
}
adminwindow.h
#ifndef ADMINWINDOW_H
#define ADMINWINDOW_H
#include <QMainWindow>
namespace Ui {
class AdminWindow;
}
class AdminWindow : public QMainWindow
{
Q_OBJECT
public:
explicit AdminWindow(QWidget *parent = 0);
~AdminWindow();
private:
Ui::AdminWindow *ui;
};
#endif // ADMINWINDOW_H
adminwindow.cpp
#include "adminwindow.h"
#include "ui_adminwindow.h"
AdminWindow::AdminWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::AdminWindow)
{
ui->setupUi(this);
}
AdminWindow::~AdminWindow()
{
delete ui;
}
Related
When I try to add any new widget to layout my program crashes. What could be the problem?
I have a pointer to QLabel as a data member of MainWindow. In constructor I allocate memory for it and that try to add it to layout. I really don't know what is the problem, cause I did this method before and it worked.
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QLabel>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow {
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private:
QLabel* tempLabel;
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
tempLabel = new QLabel("QLabel 2");
ui->widget->layout()->addWidget(tempLabel);
ui->setupUi(this);
}
MainWindow::~MainWindow() {
delete ui;
}
Error msg
I try to switch between two different Widgets in QT5.
The first problem was that my first window was visible in the background of my second window. I solve this with a check in "autoFillBackground". Now i can switch between them, but if i resize them it only resize the Main content.
Both Widgets have a grid layout.
Resize Problem
Im new at QT5, so is there a better way to make a switching between 2 widgets without this problem?
I try it with wMessages = new Messages(); and hide() but then my program crash after going back.
Code:
mainwindow.h:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "messages.h"
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private slots:
void on_btnMessages_clicked();
private:
Ui::MainWindow *ui;
Messages *wMessages;
};
#endif // MAINWINDOW_H
mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_btnMessages_clicked()
{
wMessages = new Messages(this);
wMessages->show();
}
messages.h:
#ifndef MESSAGES_H
#define MESSAGES_H
#include <QWidget>
namespace Ui {
class Messages;
}
class Messages : public QWidget
{
Q_OBJECT
public:
explicit Messages(QWidget *parent = nullptr);
~Messages();
QString NewsGenerator();
private slots:
void on_bBack_clicked();
void on_pushButton_clicked();
private:
Ui::Messages *ui;
};
#endif // MESSAGES_H
messages.cpp:
#include "messages.h"
#include "ui_messages.h"
Messages::Messages(QWidget *parent) :
QWidget(parent),
ui(new Ui::Messages)
{
ui->setupUi(this);
}
Messages::~Messages()
{
delete ui;
}
void Messages::on_bBack_clicked()
{
this->close();
QWidget *parent = this->parentWidget();
parent->show();
}
Edit 1 - working Main Window Button (from G.M.´s answer):
void MainWindow::on_btnMessages_clicked()
{
wPlaner = new Planer();
QMainWindow::setCentralWidget(wPlaner);
}
Update (based on the comments):
The best solution was to use the QStackedWidget to navigate between the views.
Docu: https://doc.qt.io/qt-5/qstackedwidget.html#details
Example-Code for Button:
// return back to first view
void MainWindow::on_btnret_clicked()
{
ui->stackedWidget->setCurrentIndex(0);
}
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!
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.
I am using Qt in my project and facing some difficulty in accessing ui label from other class,I have mainwindow and Yar class as shown below.
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "yar.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
Yar b;
private:
Ui::MainWindow *ui;
public slots:
void dispal();
private slots:
void on_pushButton_clicked();
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QObject::connect(ui->pushButton,SIGNAL(clicked()),&b,SLOT(lll()));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::dispal(){
ui->label->setText("hello");
}
Yar.h
#ifndef YAR_H
#define YAR_H
#include <QObject>
class Yar : public QObject
{
Q_OBJECT
public:
explicit Yar(QObject *parent = 0);
public slots:
void lll();
};
#endif // YAR_H
void MainWindow::on_pushButton_clicked()
{//ui->label->setText("hello");
//b.wrrrot();
//dispal();
}
Yar.cpp
#include "yar.h"
#include <iostream>
Yar::Yar(QObject *parent) :
QObject(parent)
{
//setupUi(this);
//QObject::connect(&a, SIGNAL(dis), &a, SLOT(dispal()));
//emit wrrrot();
}
void Yar::lll(){
//emit wrrrot();
std::cout<<"gfggdf"<<std::endl;
}
In my gui i have one push button and one label, I have connected push button with lll() function of class Yar and when I click push button it is displaying gfggdf in console but I want to display this text in ui label, could you please help me how can I display my data in ui label from function lll();
One possible solution is to emit signal from Yar::lll() i.e.
emit updateLabelText("your text");
And connect this signal to the slot that handles GUI (changes label with given text) in the MainWindow.
I am currently learning Qt and I seem to have run into a problem.
In my practice project I have 2 classes: MainWindow and Dialog.
MainWindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "dialog.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_pushButtonDialog_clicked();
private:
Ui::MainWindow *ui;
Dialog *dialogInstance;
};
#endif // MAINWINDOW_H
MainWindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
dialogInstance = new Dialog(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButtonDialog_clicked()
{
dialogInstance->show();
}
Dialog.h
#ifndef DIALOG_H
#define DIALOG_H
#include <QDialog>
namespace Ui {
class Dialog;
}
class Dialog : public QDialog
{
Q_OBJECT
public:
explicit Dialog(QWidget *parent = 0);
~Dialog();
private:
Ui::Dialog *ui;
};
#endif // DIALOG_H
Dialog.cpp
#include "dialog.h"
#include "ui_dialog.h"
Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
}
Dialog::~Dialog()
{
delete ui;
}
My goal is to input a value using the Dialog window, then have the value of that input shown on the MainWindow, I know how to pass variables around within the class using widgets, but I am not sure how to transfer variables between unrelated objects.
Any input would be of great help.
Try this:
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
connect(ui->pushButtonDialog, SIGNAL(clicked()), this, SLOT(on_pushButtonDialog_clicked()));
dialogInstance = new Dialog(this);
}
// ...