Java - 重绘不工作

Question

So I am making a Text-Based RPG Applet in Java. I am using SWING panels, with text fields and buttons on it. I am programming it in Netbeans, and I am using the GUI editor. I have crafted the HTML page and it opens in the browser fine. When I click a button to switch panels (basically set the first the non-visible), the new panel doesn't load. I tried using repaint() and validate() but it just doesn't work..... Any help?

package applettest;

import javax.swing.UIManager;

public class NewApplet extends java.applet.Applet {

    startScreen ss;
    registerScreen rs;
    charactercreationScreen ccs;

    @Override
    public void init() {

        try {
            //This sets the look and feel to NIMBUS.
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {

                @Override
                public void run() {
                    initComponents();
                    startup();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );
    }// </editor-fold>                        
    // Variables declaration - do not modify                     
    // End of variables declaration                   

    public void startup() {
        showCharacterCreationScreenSTART();
        showRegisterScreenSTART();
        showStartScreenSTART();
    }

    public void showStartScreen() {
        setSize(410, 350);
        ss = new applettest.startScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ss, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ss, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
    }

    public void showStartScreenSTART() {
        setSize(410, 350);
        rs.setVisible(false);
        ss = new applettest.startScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ss, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ss, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        repaint();
        validate();
    }

    public void showRegisterScreen() {
        repaint();
        validate();
        ss.setVisible(false);
        setSize(400, 350);
        rs = new applettest.registerScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(rs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(rs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        repaint();
        validate();
    }

    public void showRegisterScreenSTART() {
        repaint();
        validate();
        ccs.setVisible(false);
        setSize(400, 350);
        rs = new applettest.registerScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(rs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(rs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        repaint();
        validate();
    }

    public void showCharacterCreationScreen() {
        rs.setVisible(false);
        setSize(400, 350);
        ccs = new applettest.charactercreationScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ccs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ccs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        repaint();
        validate();

    }

    public void showCharacterCreationScreenSTART() {
        setSize(400, 350);
        ccs = new applettest.charactercreationScreen(this);
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ccs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));
        layout.setVerticalGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
                addComponent(ccs, javax.swing.GroupLayout.PREFERRED_SIZE,
                javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE));

    }
}

Answer 1

Sounds like you should be using CardLayout .

See also:

• How to Use CardLayout
• Java UI, trying to go to next page upon clicking button
• Dynamically Add Components to a JDialog

Answer 2

I tried using repaint() and validate() but it just doesn't work

FYI, when using Swing it should be:

panel.revalidate();
panel.repaint(); // sometimes needed

although that code is generally used when adding/removing individual components from a panel. If you are swapping entire panels then CardLayout is the way to go.

Also, you should be extending JApplet, NOT Applet.