Problem with Checkbox and CheckboxGroup?

[Vanchi Nathan]

Hello all,

The code below display a button and 3 option (radio) buttons. The program must uncheck the selected radio button when the button is clicked. Actually nothing happens in this code, that is the selected radio button has no change. Can anyone give a helping hand.

regards,

import java.awt.*;
import java.awt.event.*;
 
public class CheckGroupDemo extends Frame {

private CheckboxGroup cg;
private Checkbox[] cb;
private String[] cbLbl = { "Red", "Blue" ,"Green" };
private Button cancel;

public CheckGroupDemo () {
super("Checkbox Group Demo");
Panel p = new Panel();
cg = new CheckboxGroup();

p.setLayout(new GridLayout(3,1));

cb = new Checkbox[cbLbl.length];
for (int i=0; i<cbLbl.length; i++) {
cb[i] = new Checkbox(cbLbl[i],cg,false);
p.add(cb[i]);
}


cancel = new Button("Clear All");
cancel.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
for (int i=0; i<cbLbl.length; i++) {
cb[i].setCheckboxGroup(cg);
cb[i].setState(false);
}
}
});

setLayout(new BorderLayout());
add(cancel,"North");
add(p,"Center");
pack();

}

public static void main(String[] a) {
CheckGroupDemo app = new CheckGroupDemo();
app.setVisible(true);
app.addWindowListener(new WindowAdapter () {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}

}

[Craig Wood]

According to the api there will always be one checkbox in the CheckboxGroup selected. The usual way to be able to have no selections is to add another checkbox to the group but do not display it in your gui. When you want to have no selections you can select the extra checkbox.