I want to use layout in qt5, but In Visual Studio 2015 the layout does not work?
Here is my code:
layout.h code
#ifndef LAYOUT_H
#define LAYOUT_H
#include <QtWidgets/QMainWindow>
#include "ui_layout.h"
class layout : public QMainWindow
{
Q_OBJECT
public:
layout(QWidget *parent = 0);
~layout();
private:
Ui::layoutClass ui;
};
#endif // LAYOUT_H
main.cpp
#include "layout.h"
#include <QtWidgets/QApplication>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QHBoxLayout>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
layout w;
QHBoxLayout hb;
QPushButton b("button 0");
QPushButton b1("button 1");
hb.addWidget(&b);
hb.addWidget(&b1);
w.setLayout(&hb);
w.show();
return a.exec();
}
Here is my result:
How to fix this problem?
QMainWindow is a special widget since it has default widgets like QStatusbar, QMenuBar, etc. When working with this widget we must place the new elements in the centralWidget.
So we must assign a widget that will be our centralWidget, and then to this we add the layouts as shown below:
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
layout w;
w.setCentralWidget(new QWidget);
QHBoxLayout hb;
QPushButton b("button 0");
QPushButton b1("button 1");
hb.addWidget(&b);
hb.addWidget(&b1);
w.centralWidget()->setLayout(&hb);
w.show();
return a.exec();
}
Related
I have a QTreeView and I can't find a way of making it fill the whole dialog window and resize with the window when it is resized.
Something like this:
#include <QApplication>
#include <QDialog>
#include <QHBoxLayout>
#include <QTreeView>
class MyDialog: public QDialog
{
public:
MyDialog()
{
QHBoxLayout* l = new QHBoxLayout(this);
setLayout(l);
QTreeView* v = new QTreeView(this);
l->addWidget(v);
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyDialog d;
d.exec();
return a.exec();
}
I'd like to show and then close a dialog after 5 seconds. The dialog needs to be automatically resized (horizontally and vertically) based on the content of a label. Here is my code:
#include <QApplication>
#include <QDialog>
#include <QLabel>
#include <QTimer>
void notify (int intTime=1000)
{
QDialog notify;
notify.setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
notify.setWindowFlag(Qt::FramelessWindowHint);
QLabel *lbl = new QLabel(¬ify);
lbl->setText("This is a test This is a test This is a test This is a test This is a test This is a test This is a test");
QApplication::processEvents();
notify.adjustSize();
QTimer::singleShot(intTime, ¬ify, SLOT(close()));
notify.exec();
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
notify(5000);
exit(0);
// return a.exec();
}
It does not not expand the dialog based on the label size. Here is how it looks:
How can I fix it? (Please also let me know if there is better way of doing this.)
I am using Qt5 in Linux.
Since you have not used a QLayout the QLabel will be displayed as large as you can, a possible request is to change the size of QDialog to the recommended size of QLabel with sizeHint():
#include <QApplication>
#include <QDialog>
#include <QLabel>
#include <QTimer>
void notify (int intTime=1000)
{
QDialog notify;
notify.setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
notify.setWindowFlag(Qt::FramelessWindowHint);
QLabel *lbl = new QLabel(¬ify);
lbl->setText("This is a test This is a test This is a test This is a test This is a test This is a test This is a test");
QApplication::processEvents();
notify.resize(lbl->sizeHint());
QTimer::singleShot(intTime, ¬ify, SLOT(close()));
notify.exec();
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
notify(5000);
exit(0);
// return a.exec();
}
The other possible solution is to use a QLayout:
#include <QApplication>
#include <QDialog>
#include <QLabel>
#include <QTimer>
#include <QVBoxLayout>
void notify (int intTime=1000)
{
QDialog notify;
QVBoxLayout *lay = new QVBoxLayout(¬ify);
//notify.setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
notify.setWindowFlag(Qt::FramelessWindowHint);
QLabel *lbl = new QLabel;
lay->addWidget(lbl);
lbl->setText("This is a test This is a test This is a test This is a test This is a test This is a test This is a test");
QApplication::processEvents();
QTimer::singleShot(intTime, ¬ify, SLOT(close()));
notify.exec();
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
notify(5000);
exit(0);
// return a.exec();
}
I am using the Urho3D engine with Qt for an application. The problem is that both Urho3D and QApplication require to be ran from main(). For now I am using it in separate processes but IPC makes it complicated.
Is there any way to solve this issue? Thanks
My platform is Urho3D 1.5, Qt 4.71 and Windows 7 x64 and VS2015 (C++)
I'm new to both c++ and Urho3D, but I've successfully achieved it.
Simple code, haven't had further test:
awidget.h:
#ifndef AWIDGET_H
#define AWIDGET_H
#include <QWidget>
#include <QPushButton>
#include <Urho3D/Engine/Application.h>
class aWidget : public QWidget
{
Q_OBJECT
public:
explicit aWidget(QWidget *parent = 0)
{
QPushButton *button = new QPushButton(this);
connect(button, SIGNAL(clicked()), this, SLOT(pressed()));
}
public slots:
void pressed()
{
Urho3D::Context* context = new Urho3D::Context();
Urho3D::Application *application = new Urho3D::Application(context);
application->Run();
}
};
#endif // AWIDGET_H
main.cpp:
#include <QApplication>
#include <awidget.h>
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
aWidget *widget = new aWidget();
widget->show();
return app.exec();
}
By the way, I'm using Qt 5.9.0
So the answer is quite simple. Instead of running QApplication by calling
app->exec();
it is needed to manually and regularily call this from your main loop:
app->processEvents();
This will take care that all events used by Qt are processed and QApplication will respond accordingly.
Example:
#include <QApplication>
#include <awidget.h>
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
bool shallrun = true;
aWidget *widget = new aWidget();
widget->show();
while (shallrun)
{
app->processEvents();
...
}
...
}
I am trying to hide my QT application from taskbar? I cannot find anything in Google so I asking here.
Solution from Qt Hide Taskbar Item (Qt Hide Taskbar Item) and this->hide() is not helping.
main.cpp
#include "status_bar.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
status_bar w;
w.show();
return a.exec();
}
status_bar.cpp:
#include "status_bar.h"
#include "ui_status_bar.h"
#include <stdlib.h>
#include <QTime>
#include <QTimer>
#include <QApplication>
#include <QDesktopWidget>
status_bar::status_bar(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::status_bar)
{
ui->setupUi(this);
setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
resize(QApplication::desktop()->width(),36);
ui->time->move(QApplication::desktop()->width()-ui->time->size().width(),10);
ui->username->setText(getenv("USER"));
timeupdate = new QTimer(this);
connect(timeupdate, SIGNAL(timeout()),
this, SLOT(UpdateClock()));
timeupdate->start(100);
}
void status_bar::UpdateClock()
{
ui->time->setText(QTime::currentTime().toString("HH:mm"));
}
status_bar::~status_bar()
{
delete ui;
}
EDIT:
With code like this window is empty.
class MyWindowWidget : public QWidget
{
public:
MyWindowWidget(QWidget *parent)
: QWidget(parent, Qt::Dialog)
{
}
};
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
status_bar window;
MyWindowWidget widget(&window);
widget.show();
return app.exec();
}
Solved by using Qt::Tool flag.
Qt::Tool flag has other problems for me, like this widget/windows is hidden when its state becomes inactive.
I would recommend you to use Qt::ToolTip
I am getting an error while trying to run this Application ... the error message is:
main.cpp(11): error: expression must have class type
int r = dialog.exec(); and I am not sure why!!!
I am using qmake to generate the make file... I have added the necessary files to the *.pro file since Dialog is inherited from QDialog I should have access to the function exec!
#include <QtGui>
#include <QDialog>
#include <QtUtil.h>
#include <Mathematics.h>
#include <Pair.h>
#include "View.h"
class QMesseageBox;
class QAction;
class QDialogButtonBox;
class QLabel;
class QLineEdit;
class QPushButton;
class QTextEdit;
class Dialog : public QDialog {
Q_OBJECT
public:
Dialog() {
QHBoxLayout *layout = new QHBoxLayout;
// prevent left vertical box from growing when main window resized
layout->addStretch(1);
QLabel* lab_Layers = new QLabel(tr("Layers"));
d_inline = new QLineEdit;
d_inline->setText("50");
scene = new QGraphicsScene(0, 0, 500, 500);
view = new View;
layout->addWidget(view);
view->setScene(scene);
QVBoxLayout *mainLayout = new QVBoxLayout;
mainLayout->addLayout(layout);
setLayout(mainLayout);
setWindowTitle(tr("VI Smooth 0.4"));
}
private slots:
// scroll the "after" window when "before" one is scrolled (so they
// remain in sync)
private:
QAction* exitAction;
QtUtil qt;
QLineEdit* d_inline;
QGraphicsScene* scene;
QGraphicsView* view;
};
main class
#include <QApplication>
#include <QMessageBox>
#include "Dialog.h"
int
main(int argc, char **argv) {
QApplication app(argc, argv);
argv++;
Dialog dialog();
// dialog.showMaximized();
int r = dialog.exec();
return 0;
}
It should look something like this. If you create a Dialog object, you need to call show(). And you also need to return app.exec() in main().
#include <QApplication>
#include <QMessageBox>
#include "Dialog.h"
int
main(int argc, char **argv) {
QApplication app(argc, argv);
argv++;
Dialog dialog;
dialog.show()
return app.exec(argc, argv);
}