CODEWITHSUNDEEP
javaswingradio-buttonawtbackground-color
Akshat Malviya
Akshat Malviya

Reputation: 13

JButton variable not found

I am trying to change the background color on click of a radio button, but the second radio button, "bt2" variable is not found by the compiler.

I keep getting this error message:

"cannot find symbol bt1" in the e.getSource()==bt1

Here is my code:

public class ColorChooser extends JFrame implements ActionListener {

    public static void main(String[] args) {
        new ColorChooser();
    }

    public ColorChooser() {
        super("ColorChooser");
        Container content = getContentPane();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());
        JRadioButton bt1 = new JRadioButton("Red");
        JRadioButton bt2 = new JRadioButton("Yellow");

        bt1.addActionListener(this);
        bt2.addActionListener(this);
        content.add(bt1);
        content.add(bt2);
        setSize(300, 100);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == bt1)
            getContentPane().setBackground(Color.RED);
        else
            getContentPane().setBackground(Color.YELLOW);
    }
}

Upvotes: 1

Views: 170

Answers (2)

Madhawa Priyashantha
Madhawa Priyashantha

Reputation: 9872

declare bt1 outside of constructor

JRadioButton bt1;

then initialize inside constructor

bt1 = new JRadioButton("Red");

the problem in your code is bt1 is not visible to outside of constructor.it's declared as a block variable.you should declare as instance varible [in class area]. example

public class ColorChooser extends JFrame implements ActionListener {

    JRadioButton bt1;//declare

    public static void main(String[] args) {
        new ColorChooser();
    }

    public ColorChooser() {
        super("ColorChooser");
        Container content = getContentPane();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());
        bt1 = new JRadioButton("Red");//initializing
        JRadioButton bt2 = new JRadioButton("Yellow");

        bt1.addActionListener(this);
        bt2.addActionListener(this);
        content.add(bt1);
        content.add(bt2);
        setSize(300, 100);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == bt1) {
            getContentPane().setBackground(Color.RED);
        } else {
            getContentPane().setBackground(Color.YELLOW);
        }

    }

}

Upvotes: 1

Alexandr Radchykov
Alexandr Radchykov

Reputation: 166

You should declare your bt1 as instance variable Like that 

public class ColorChooser extends JFrame implements ActionListener
{  
    private JRadioButton bt1;
...
}

Upvotes: 2

Related Questions