简体   繁体   中英

use actionlistener to call void function in same class

I have problem to use action listener to call function void in same class.

example.. code:

public class Product extends JPanel {

    JButton add;
    JPanel pAdd;
    JLabel test;
    JFrame frame;

    public Product() {
        add = new JButton("Add Product");
        add.addActionListener(new ButtonListener());

        add(add);
    }

    public void panelAdd(){
        pAdd = new JPanel();
        pAdd.add(new JLabel("try"));
        add(pAdd);

    }

    private class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent event) {
            panelAdd();
        }
    }
}

How to make call the panelAdd void method?

If you put

 System.out.println("hi");

to

public void panelAdd(){
  System.out.println("hi");
   pAdd = new JPanel();
   pAdd.add(new JLabel("try"));
   add(pAdd);

}

you will see hi printed to your console , your code are working, but you have problem in Layout .

When you add components to visible JFrame / JPanel /other components, you neet to call revalidate() and repaint() methods after adding. Change your panelAdd() like next:

public void panelAdd(){
    pAdd = new JPanel();
    pAdd.add(new JLabel("try"));
    add(pAdd);
    revalidate();
    repaint();
}

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM