选择了哪个 JRadioButton

Question

I have several JRadioButtons in a ButtonGroup.

   private ButtonGroup radioGroup= new ButtonGroup();
   private JRadioButton radio1= new JRadioButton("Red");
   private JRadioButton radio2= new JRadioButton("Green");
   private JRadioButton radio3= new JRadioButton("Blue");

   radioGroup.add(radio1);
   radioGroup.add(radio2);
   radioGroup.add(radio3);

How can I check which one was selected?

With System.out.println(radioGroup.getSelection()) I only get something like javax.swing.JToggleButton$ToggleButtonModel@32b3714 .

Answer 1

From the selected ButtonModel, you can get the actionCommand String (if you remember to set it.).

// code not compiled, run, nor tested in any way
ButtonModel model = radioGroup.getSelection();
String actionCommand = (model == null) ? "" : model.getActionCommand():
System.out.println(actionCommand);

But this will only work if you set the actionCommand first. eg,:

// code not compiled, run, nor tested in any way
String[] colors = {"Red", "Green", "Blue"};
JRadioButton[] radioBtns = new JRadioButton[colors.length];
for (int i = 0; i < radioBtns.length; i++) {
   radioBtns[i] = new JRadioButton(colors[i]);
   radioBtns[i].setActionCommand(colors[i]);
   radioGroup.add(radioBtns[i]);
   somePanel.add(radioBtns[i]);
}

Answer 2

What you're seeing is the default implementation of the toString method. And ButtonGroup#getSelection will return the ButtonModel of the selected JRadioButton .

See also How do I get which JRadioButton is selected from a ButtonGroup .

Answer 3

If listeners are attached, an easy way to determine the source is to call ActionEvent.getSource() .

Answer 4

This will return the text of selected radiobutton from buttongroup

    Enumeration<AbstractButton> allRadioButton=radioGroup.getElements();  
    while(allRadioButton.hasMoreElements())  
    {  
       JRadioButton temp=(JRadioButton)allRadioButton.nextElement();  
       if(temp.isSelected())  
       {  
          JOptionPane.showMessageDialog(null,"You select : "+temp.getText());  
       }  
    }