In this post we will see how to add the click event to the QPushbutton with an example.

samples.pro

The signal on its own does not perform any action. Instead, it is ‘connected’ to a ‘slot’. The slot can be any callable Python function. In PyQt, connection between a signal and a slot can be achieved in different ways. Following are most commonly used techniques − QtCore.QObject.connect(widget, QtCore.SIGNAL(‘signalname’), slot. Slots are funct ions defined as slot like this example: private slots: void onButtonClicked; this code on header file. And last important think is that, signals and slots must have same parameters. It works: QObject::connect(ui.comboBox, SIGNAL(activated(int)), this, SLOT(onComboboxActivated(int))).

Example SLOT/SIGNAL between two object QT. Ask Question Asked 3 years, 9 months ago. Active 3 years, 2 months ago. Viewed 5k times 1. My app, consists in 2. Slots and signals must have same parameters. Otherwise, the connection will not occur. Not only for connection, slot function must have same parameters with signal. For example, this sample doesn’t work: QObject::connect(ui.comboBox, SIGNAL (activated(int)), this, SLOT (onComboboxActivated)); But it works.

samples.pro

<table><tbody><tr><td><div><div>2</div><div>4</div><div>6</div><div>8</div><div>10</div></div></td><td><div><div><span>CONFIG</span><span>+=</span><span>c</span><span>++</span><span>11</span></div><div><span>SOURCES</span><span>+=</span><span></span></div><div><span>MyMainWindow</span><span>.</span><span>h</span></div></div></td></tr></tbody></table><p>MyMainWindow.h</p><div><textarea wrap='soft' readonly='>#ifndef MYMAINWINDOW_H #define MYMAINWINDOW_H #include <QPushButton> #include <QMessageBox> #include <QMainWindow> #include <QVBoxLayout> class MyMainWindow: public QMainWindow { Q_OBJECT public: MyMainWindow(){} ~ MyMainWindow(){} void Execute() { QPushButton *button = new QPushButton(this); QPushButton *button2 = new QPushButton(this); button->setText('Button No. 1'); button2->setText('Button No. 2'); QObject::connect(button, SIGNAL(clicked()),this, SLOT(clickedSlot())); QObject::connect(button2, SIGNAL(clicked()),this, SLOT(clickedSlot())); button->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding); button2->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding); QWidget* centralWidget = new QWidget(this); centralWidget->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding); QVBoxLayout* layout = new QVBoxLayout(centralWidget); layout->addWidget(button); layout->addWidget(button2); setCentralWidget(centralWidget); setWindowTitle('Pushbutton Clicked Signal Test'); show(); } public slots: void clickedSlot() { QMessageBox msgBox; msgBox.setWindowTitle('MessageBox Title'); msgBox.setText('You Clicked '+ ((QPushButton*)sender())->text()); msgBox.exec(); } }; #endif // MYMAINWINDOW_H

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#define MYMAINWINDOW_H

#include <QMessageBox>

#include <QVBoxLayout>

classMyMainWindow:publicQMainWindow

Q_OBJECT

public:

~MyMainWindow(){}

voidExecute()

QPushButton*button2=newQPushButton(this);

button->setText('Button No. 1');

QObject::connect(button,SIGNAL(clicked()),this,SLOT(clickedSlot()));

QObject::connect(button2,SIGNAL(clicked()),this,SLOT(clickedSlot()));

button->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);

button2->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);

QWidget*centralWidget=newQWidget(this);

centralWidget->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);

QVBoxLayout*layout=newQVBoxLayout(centralWidget);

layout->addWidget(button);

setWindowTitle('Pushbutton Clicked Signal Test');

}

publicslots:

{

msgBox.setWindowTitle('MessageBox Title');

msgBox.setText('You Clicked '+((QPushButton*)sender())->text());

}

#endif // MYMAINWINDOW_H

main.cpp

</div><h3>Signal Slots Qt Examples</h3><table><tbody><tr><td><div><div>2</div><div>4</div><div>6</div><div>8</div><div>10</div><div>12</div><div>14</div><div>16</div></div></td><td><div><div><span>#include <QMainWindow></span></div><div><span>{</span></div><div><span>MyMainWindow </span><span>window</span><span>;</span></div><div><span>window</span><span>.</span><span>setWindowTitle</span><span>(</span><span>QString</span><span>::</span><span>fromUtf8</span><span>(</span><span>'MainWindow'</span><span>)</span><span>)</span><span>;</span></div><div><span>window</span><span>.</span><span>Execute</span><span>(</span><span>)</span><span>;</span></div><div><span>return</span><span>app</span><span>.</span><span>exec</span><span>(</span><span>)</span><span>;</span></div><div><span>}</span></div></div></td></tr></tbody></table><h3>Signal Slot Qt Example</h3><p>OUTPUT</p><br><br><a href='https://amebaownd.mix-goapp.com/valley-view-casino-lunch-buffet-price.html#TXl=UAwCBAZRRgQATFdcSBkcW0YEWkIaRQhWD1lVE0JfX0wRExdAHgdKVQ9IClAUUFcEHFYVUFdbA10IVlIVBB8cCkwKVgYETgcYWxQDWxU0NRlWCUFbURgAXARaWFdGXVQWAVcLGBkWV0wWS0MGWURVVGM=' target='_blank'><img src='https://mix-goapp.com/images/pla