How to USe QPushButton: Difference between revisions

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[[Category:Developing with Qt::General]]
#REDIRECT [[How to Use QPushButton]]
[[Category:HowTo]]
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[[Category:Tutorial]]
 
[toc align_right="yes" depth="3"]
 
'''English''' [[How_to_Use_QPushButton_Bulgarian|Български]] [[How_to_Use_QPushButton_Spanish|Spanish]] [[How_to_Use_QPushButton_SimplifiedChinese|简体中文]] [[How_to_Use_QPushButton_Greek|Ελληνικά]]
[[How_to_Use_QPushButton_Russian|Русский]][[How_to_Use_QPushButton_Persian|فارسی]]
 
= How to Use QPushButton =
 
== QPushButton Overview ==
 
Using "QPushButton":http://doc.qt.io/qt-5.0/qtwidgets/qpushbutton.html developers can create and handle buttons. This class is easy to use and customize so it is among the most useful classes in Qt. In general the button displays text but an icon can also be displayed.
 
QPushButton inherits "QAbstractButton":http://doc.qt.io/qt-5.0/qtwidgets/qabstractbutton.html which inherits "QWidget":http://doc.qt.io/qt-5.0/qtwidgets/qwidget.html.
 
== Signals ==
 
=== Inherited from QAbstractButton ===
 
* void clicked ( bool checked = false )
* void pressed ()
* void released ()
* void toggled ( bool checked )
 
=== Inherited from QWidget ===
 
* void customContextMenuRequested ( const QPoint & pos )
 
=== Inherited from QObject ===
 
* void destroyed ( QObject * obj = 0 )
 
== Basic Usage ==
 
=== Text ===
 
The text of QPushButton can be set upon creation or using "setText()":http://doc.qt.io/qt-5.0/qtwidgets/qabstractbutton.html#text-prop. To get the current text of the button use "text()":http://doc.qt.io/qt-5.0/qtwidgets/qabstractbutton.html#text-prop.
 
=== Icon ===
 
The icon of QPushButton can also be set upon creation. After creation the icon can be changed using "setIcon()":http://doc.qt.io/qt-5.0/qtwidgets/qabstractbutton.html#icon-prop To get the current icon of the button use "icon()":http://doc.qt.io/qt-5.0/qtwidgets/qabstractbutton.html#icon-prop
 
=== Set Position and Size ===
 
To set the position and the size of the button use "setGeometry()":http://doc.qt.io/qt-5.0/qtwidgets/qwidget.html#geometry-prop. If you want just to modify the size of the button use "resize()":http://doc.qt.io/qt-5.0/qtwidgets/qwidget.html#size-prop.
 
=== Handle Button ===
 
QPushButton emits signals if an event occurs. To handle the button connect its appropriate signal to a slot:
 
<code>connect(m_button, SIGNAL (released()),this, SLOT (handleButton()));<code>
 
== Example ==
 
The following simple code snippet shows how to create and use QPushButton. It has been tested on Qt Symbian Simulator.
 
An instance of QPushButton is created. Signal '''released()''' is connected to slot '''handleButton()''' which changes the text and the size of the button.
 
=== mainwindow.h ===
 
</code>
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QtGui/QMainWindow>
#include <QtGui/QPushButton>
//#include <QMainWindow>//For Qt5
//#include <QPushButton>//For Qt5
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
Q_OBJECT
 
public:
explicit MainWindow(QWidget *parent = 0);
 
private slots:
void handleButton();
 
private:
QPushButton *m_button;
};
 
#endif // MAINWINDOW_H
<code>
 
=== mainwindow.cpp ===
 
</code>
#include "mainwindow.h"
 
#include <QtCore/QCoreApplication>
//#include <QCoreApplication>//For Qt5
 
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
// Create the button, make "this" the parent
m_button = new QPushButton("My Button", this);
// set size and location of the button
m_button->setGeometry(QRect(QPoint(100, 100),
QSize(200, 50)));
 
// Connect button signal to appropriate slot
connect(m_button, SIGNAL (released()), this, SLOT (handleButton()));
}
 
void MainWindow::handleButton()
{
// change the text
m_button->setText("Example");
// resize button
m_button->resize(100,100);
}
<code>
 
=== main.cpp ===
 
</code>
#include "mainwindow.h"
 
#include <QtGui/QApplication>
//#include <QApplication> //For Qt5
 
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
 
MainWindow mainWindow;
mainWindow.showMaximized();
return app.exec();
}
 
<code>
 
== See also ==
 
"Qt Buttons":http://developer.qt.nokia.com/wiki/Qt_Buttons

Latest revision as of 12:31, 19 March 2015

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