setchecked( true) of the radio button doesn't work

[richardander]

Hello,

In the UI of my application, there are several radio buttons. They work well when I click them.

However, when I use raidoButton_1->setChecked(true) to set them, UI doesn't change. Shall I call some other functions to update them?

Thank you!

[jpn]

However, when I use raidoButton_1->setChecked(true) to set them, UI doesn't change. Shall I call some other functions to update them?

No, there is no need. It should work unless you block the event loop somehow. Do you have a busy loop in your application?

[richardander]

There is no busy loop in the application.

Could you let me know what are the commands/functions in QT that can block the event loop?

Thank you!

[jpn]

Does this work for you?

// main.cpp
#include <QtGui>
 
int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QRadioButton button1("checked");
    QRadioButton button2("unchecked");
    button1.setChecked(true);
    button2.setChecked(false);
    button1.show();
    button2.show();
    return app.exec();
}

// main.cpp
#include <QtGui>

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QRadioButton button1("checked");
    QRadioButton button2("unchecked");
    button1.setChecked(true);
    button2.setChecked(false);
    button1.show();
    button2.show();
    return app.exec();
}

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Are you sure that the code where you change the check state gets actually executed?

[richardander]

Hello,

The code works. In fact, I did another test: put three radio buttons in one qgroupbox. Using setChecked( true) to select one radio button. But, if I want to clear the selection, the setChecked( false ) seems not working. In following code, first radio button is selected. But it can not be unselected.

// main.cpp
#include <QtGui>
 
int main(int argc, char* argv[])
{
 
		QApplication app(argc, argv);
 
		QGroupBox *groupBox = new QGroupBox("Exclusive Radio Buttons");
 
		QRadioButton *radio1 = new QRadioButton("&Radio button 1");
		QRadioButton *radio2 = new QRadioButton("R&adio button 2");
		QRadioButton *radio3 = new QRadioButton("Ra&dio button 3");
 
 
		QVBoxLayout *vbox = new QVBoxLayout;
		vbox->addWidget(radio1);
		vbox->addWidget(radio2);
		vbox->addWidget(radio3);
		vbox->addStretch(1);
		groupBox->setLayout(vbox);
 
		groupBox->show();
 
		radio1->setChecked(true);
 
		radio1->setChecked(false);
 
 
		return app.exec();
}

// main.cpp
#include <QtGui>
 
int main(int argc, char* argv[])
{

		QApplication app(argc, argv);

		QGroupBox *groupBox = new QGroupBox("Exclusive Radio Buttons");

		QRadioButton *radio1 = new QRadioButton("&Radio button 1");
		QRadioButton *radio2 = new QRadioButton("R&adio button 2");
		QRadioButton *radio3 = new QRadioButton("Ra&dio button 3");


		QVBoxLayout *vbox = new QVBoxLayout;
		vbox->addWidget(radio1);
		vbox->addWidget(radio2);
		vbox->addWidget(radio3);
		vbox->addStretch(1);
		groupBox->setLayout(vbox);

		groupBox->show();

		radio1->setChecked(true);

		radio1->setChecked(false);

		
		return app.exec();
}

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Is there any way to make no radiobutton selected?

Thank you!

[spirit]

put needed radiobutons in QGroupBox.

[richardander]

As shown in the above sample code, the three radio buttons have been put in the QGroupBox so that only one radiobutton can be selected.

however, if I want to clear the current selection and make all radiobutton unselected, what shall I do?

thank you!

[spirit]

try to add the following code to yours

...
radio1->setCheckable(false);
radio2->setCheckable(false);
radio3->setCheckable(false);
...

...
radio1->setCheckable(false);
radio2->setCheckable(false);
radio3->setCheckable(false);
...

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but in this case you can't be able to check buttons at all.

[jpn]

Radio buttons are "auto-exclusive" by default. If auto-exclusive is enabled, radio buttons that belong to the same parent widget behave as if they were part of the same exclusive button group.

[richardander]

Thank you!