How to Switch between Panels in CardLayout from ActionListeners in external classes

问题

I have a cardLayout in the main class that the Gui classes are added to layout via panels and when the Room1Button is pressed how would it switch the card in the main method to the Gui2 card

is this the best way to go about this any help would be apreatiated

Main Method

  import javax.swing.*;
  import java.awt.*;
  class Main
  {

CardLayout cl=new CardLayout();
GridBagConstraints gb=new GridBagConstraints();
JFrame frame=new JFrame("Frame");
JPanel panel =new JPanel();


Gui1 g1= Gui1();
Gui2 g2= Gui2();


public Main()
{
   panel.setLayout(cl);
   panel.add(g1, "1");
   panel.add(g2, "2");

    frame.add(panel);
    frame.pack();
    frame.setVisible(true);

    cl.show(panel,"1");

    //how would the actionlistner in the Gui1 class switch the layout to "2"

    cl.show(panel, "2");


}


public static void main(String[]param)
{
    new Main();


}


}

The gui1 class

 import javax.swing.*;
 import java.awt.*;
 import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
 import java.util.*;


 public class Gui1 extends JPanel implements ActionListener{


private JButton room1Button;

JPanel panel=new JPanel();

{



    setSize(1000,1000);

    panel.setVisible(true);

    room1Button=new JButton("Go the next Panel");

    this.setVisible(true);
    room1Button.addActionListener(this);
    add(room1Button);


}

@Override
public void actionPerformed(ActionEvent e) {

    if(e.getSource()==room1Button){
       Window w = SwingUtilities.getWindowAncestor(R0.this);
       w.setVisible(false);

    }

}
}

The Gui2 class

 public class Gui2 extends JPanel implements Actionlistener
 {
        // some code

 }

回答1:

The ActionEvent will contain the source object that generated the event. In this case the JButton. So generic code for the ActionListener in your GUI1 class would be something like:

JButton button = (JButton)e.getSource();
JPanel buttonPanel = (JPanel)button.getParent();
JPanel cardLayoutPanel = (JPanel)buttonPanel.getParent();
CardLayout layout = (CardLayout)cardLayoutPanel.getLayout();
layout.show(cardLayoutPanel, "2");

回答2:

Hope this helps.

package cardlayoutsample;

import java.awt.CardLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class CardLayoutSample {
    JFrame frame = new JFrame("CardLayout Demo");
    JPanel panelCont = new JPanel();
    JPanel panelFirst = new JPanel();
    JPanel panelSecond = new JPanel();
    JButton btnOne = new JButton("Switch");
    JButton btnTwo = new JButton("Back");

    CardLayout cl = new CardLayout();

    public CardLayoutSample(){
        panelCont.setLayout(cl);

        panelFirst.add(btnOne);
        panelSecond.add(btnTwo);
        panelFirst.setBackground(Color.red);
        panelSecond.setBackground(Color.blue);

        panelCont.add(panelFirst,"1");
        panelCont.add(panelSecond,"2");
        cl.show(panelCont, "1");

        btnOne.addActionListener(new ActionListener(){

        public void actionPerformed(ActionEvent arg0){
            cl.show(panelCont, "2");
        }
    });

        btnTwo.addActionListener(new ActionListener(){

        public void actionPerformed(ActionEvent arg0){
            cl.show(panelCont, "1");
        }
    }); 

        frame.add(panelCont);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
        frame.setLocationRelativeTo(null);
    }

    public static void main(String[] args) {
    CardLayoutSample a = new CardLayoutSample();
    }
}

Try to play this button you can see it's switching the panels when you clicked the buttons.

Syntax for ActionListener

Component.addActionListener(new ActionListener (){
@Override
  public void actionPerformed(ActionEvent e){
  //do this
 }
});

Example

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

来源：https://stackoverflow.com/questions/36283545/how-to-switch-between-panels-in-cardlayout-from-actionlisteners-in-external-clas