how do I use Actionlisten? I need an example to better understand

Question

Guys, in a previous question I had asked a question about actionListen, but I wanted to ask an example, could someone give me an example, I created this simple code q shows a Jbutton in Swing, wanted someone to give me an example like...

simple code I created:

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JLabel;

public class inicio{

    public static void main(String[] args){

       JFrame frame = new JFrame("Tela de incio");
       JPanel painel = new JPanel();
       JButton confirm = new JButton("CONFIRMAR");
       frame.add(painel);
       painel.add(confirm);
       confirm.setBounds(10,10,10,10);
       frame.setSize(600,600);
       frame.setVisible(true);


    }

}

Answer 1

Hello @joaoazevedo, I’ll explain in my brief how it works and give an example of Actionlistener.

So, Actionlistener is a code that allows you to give an action to an object... For example here I defined that the variable 'exit' will have an action to give an 'Exit' in the programming.

• Actionlistener = creates a list of events for the object.

• Actionevent = creates the variable list event and inside the event is placed its respective action...

  sair.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) {
          System.exit(0);
      }
  });
  

Here I’ll complete my programming if you want to copy and run your tests in your IDE.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class telaPrincipal extends JFrame{
private Container c1;
private JButton sair, inicio;
private ImageIcon img1;
private JLabel imgfundo, logo;
Quiz frame = new Quiz();

public telaPrincipal() {
    inicializarComponentes();
    definirEventos();
}

private void inicializarComponentes() {
    setLayout(null);

    c1 = getContentPane();
    getContentPane().setBackground(Color.black);
    img1 = new ImageIcon(getClass().getResource("telaprincipal2.gif"));         
    imgfundo = new JLabel(img1);

    inicio = new JButton("Iniciar");

    sair = new JButton("Sair");
    sair.setMnemonic('S');

    logo =  new JLabel("QUIZ PROGRAMER FOR PROGRAMERS");
    logo.setForeground(Color.white); 
    logo.setFont(new Font ("SansSerif", Font.ITALIC, 50));
    logo.setBounds(5,20,1500,60);

    inicio.setFont(new Font("Arial", Font.BOLD, 60));
    inicio.setForeground(Color.white);
    inicio.setOpaque           (false);
    inicio.setContentAreaFilled(false);
    inicio.setBorderPainted    (false);

    sair.setFont(new Font("Arial", Font.BOLD, 60));
    sair.setForeground(Color.white);
    sair.setOpaque           (false);
    sair.setContentAreaFilled(false);
    sair.setBorderPainted    (false);
    imgfundo.setBounds(0,20,960,740);
    inicio.setBounds(360,260,250,80);
    sair.setBounds(360,460,250,80);
    add(logo);
    add(inicio);
    add(sair);
    add(imgfundo);
}
public void definirEventos() {
    sair.addActionListener(new ActionListener() { 
        public void actionPerformed(ActionEvent e) {
            System.exit(0);
        }
    });

    inicio.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            //Quiz p1 = new Quiz();
            //p1.validate();
            //c1.add(p1);
            //c1.removeAll();
            //c1.validate();
        } 
    });
}

public static void main(String args[]) {

    telaPrincipal frame = new telaPrincipal();
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     frame.setUndecorated(true);
     frame.setBounds(200,0,960,740);
     frame.setVisible(true);

  }
}

I hope very much to have helped, if you are in doubt do not hesitate to ask.