Qt menubar disappears when I use scroll area
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I want to implement a vertical scroll bar. I have implemented layouts for this(see the attached layouts.jpg), and also scroll area(see snippet in below code). Yet, when I run, the window does not have menubar. What am I missing here? I tried adding the menubar and submenus through Qt designer, as well as through code, but the window does not show the menubar.
If i use scroll area snippet, i can use the scrollbar, but don't see menubar. However If i comment out the scroll area snippet, i can see the menubar, but lose the scroll bar. I need both of them. How to solve this?
"Your text to link here...":http://i.stack.imgur.com/Nj9OG.jpg
Here is the code:-
mainwindow.h
@#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QScrollArea>
namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{
Q_OBJECTpublic:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();private:
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)
{
ui->setupUi(this);
layout()->setMenuBar(menuBar());
QMenu *viewMenu;
viewMenu = menuBar()->addMenu("VIEW");
QMenu *resolutionSubMenu = viewMenu->addMenu("Resolution");
QAction *QVGA = resolutionSubMenu->addAction("QVGA");QImage image(":\\image.jpg"); ui->referenceImageLabel->setPixmap(QPixmap::fromImage(image)); ui->deltaImageLabel->setPixmap(QPixmap::fromImage(image)); ui->reconstructedImageLabel->setPixmap(QPixmap::fromImage(image)); ui->referenceImageLabel->setMinimumSize(480, 640);ui->referenceImageLabel->setMinimumSize(480, 640);ui->referenceImageLabel->setMinimumSize(480, 640); /*Scroll area snippet*/ QScrollArea *p_ScrollArea = new QScrollArea(this); p_ScrollArea->setAutoFillBackground(true); p_ScrollArea->setMinimumSize(width(), height()); p_ScrollArea->setWidget(ui->centralWidget);
}
MainWindow::~MainWindow()
{
delete ui;
}@main.cpp
@
#include "mainwindow.h"
#include <QApplication>int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();return a.exec();
}@
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Hi,
Why ?
@layout()->setMenuBar(menuBar());@
The menu bar is already put at the right place for you when you use a QMainWindow
@
QScrollArea *p_ScrollArea = new QScrollArea(this);
p_ScrollArea->setAutoFillBackground(true);
p_ScrollArea->setMinimumSize(width(), height());
p_ScrollArea->setWidget(ui->centralWidget);
@You scroll area is just floating.
Since you already use Designer to create your UI, why don't you also setup the scroll area and menus there ?
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Hi SGaist,
For the 1st question, when i added menubar through the designer, and run the program, the menubar was not there. so i added the line programmatically, but that did not help either.For the 2nd question, i do not know how to implement scroll bar for three qlabels through designer mode. If you have a tutorial where multiple qlables can be scrolled using a single vertical or horizontal scrollbar, through designer mode, and can share, i'd be most grateful.
Also, what's a floating scroll area?
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The first thing you should do is have a look at Qt's example and tutorials you should then be able to create your widget.
It's floating in the sense that you didn't set it as central widget nor in a layout thus you have to handle it's size and position by hand.