Event click button

Question

I add a few buttons like this:

JButton bt;
for(int i = 0; i <= 10; i++){
    bt = new JButton("BT : " + i);
    bt.setPreferredSize(new Dimension(80, 80));
    bt.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            // fazer algo
        }
    });

    jPanel.add(bt);
}

I need an action for each button, let me give you a very simple example. Let’s assume that I have a 10 position vector, with numbers from 1 to 10. That is, I have a position in the vector for each button inserted. When clicking on the right button display the vector position number for the clicked button.

Button 1 - displays vector position 1 Boot 2 - displays vector position 2 Boot 3 - displays position 3 of vector .... and so on

How can I do this in the boot click event?

Answer 1

Keep everything in the loop and declare a final with what you want to write/manipulate.

for(int i = 0; i <= 10; i++){
    JButton bt = new JButton("BT : " + i);
    final Integer valor = Integer.valueOf(i);
    bt.setPreferredSize(new Dimension(80, 80));
    bt.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            System.out.println("Valor : " + valor);
        }
    });
    jPanel.add(bt);
}

Answer 2

Use the method setActionCommand() to set an action for the button. Then you can take this value when the event is triggered:

for(int i = 0; i <= 10; i++){
    bt = new JButton("BT : " + i);
    bt.setActionCommand(String.valueOf(i));
    bt.setPreferredSize(new Dimension(80, 80));
    bt.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            System.out.println("Índice: " + e.getActionCommand());
        }
    });
    jPanel.add(bt);
}

If you need that amount as int, can use the method Integer#parseInt.