How do I pass data between cards in Java CardLayout

问题

I am new to working with Java GUI, I know this may sound ridiculous but I have been trying for days to pass data between cards on the CardLayout layout. I am using netbeans, the first card displays a list clients. When a client is selected, the choice selection is passed to a variable on that card. The next card queries the database to show more details about the client selected. I can handle the switching between cards but my problem is I can't pass the data stored in the variable on card 1 to card 2.

I have visited several forums and read through similar questions asked but I just cannot get any of the proposed solutions to work. Please help, I'm new at this so please go easy on me, thanks.

Here is the class that holds the panels

public class mainframe extends javax.swing.JFrame {

public mainframe() {
    initComponents();
}



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

    displayScrollPane = new javax.swing.JScrollPane();
    displaypanel = new javax.swing.JPanel();
    viewclientspanel1 = new viewclientspanel();
    addclientpanel1 = new addclientpanel();
    clientdetails1 = new clientdetails();
    mainmenu = new javax.swing.JMenuBar();
    clients = new javax.swing.JMenu();
    viewclients = new javax.swing.JMenuItem();
    addclient = new javax.swing.JMenuItem();
    transactions = new javax.swing.JMenu();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    displaypanel.setBorder(javax.swing.BorderFactory.createEtchedBorder());
    displaypanel.setLayout(new java.awt.CardLayout());

    viewclientspanel1.addMouseListener(new java.awt.event.MouseAdapter() {
        public void mouseClicked(java.awt.event.MouseEvent evt) {
            viewclientspanel1MouseClicked(evt);
        }
    });
    displaypanel.add(viewclientspanel1, "viewclientscard");
    displaypanel.add(addclientpanel1, "addclientcard");
    displaypanel.add(clientdetails1, "clientdetailscard");

    displayScrollPane.setViewportView(displaypanel);

    clients.setText("Clients");

    viewclients.setText("View Clients");
    viewclients.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            viewclientsActionPerformed(evt);
        }
    });
    clients.add(viewclients);
    viewclients.getAccessibleContext().setAccessibleParent(mainmenu);

    addclient.setText("Add Client");
    addclient.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            addclientActionPerformed(evt);
        }
    });
    clients.add(addclient);

    mainmenu.add(clients);

    transactions.setText("Transactions");
    mainmenu.add(transactions);

    setJMenuBar(mainmenu);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(displayScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 1059, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(99, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap(66, Short.MAX_VALUE)
            .addComponent(displayScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 570, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(33, 33, 33))
    );

    pack();
}// </editor-fold>

private void addclientActionPerformed(java.awt.event.ActionEvent evt) {                                          
    CardLayout card = (CardLayout) displaypanel.getLayout();
    card.show(displaypanel, "addclientcard");
}                                         

private void viewclientsActionPerformed(java.awt.event.ActionEvent evt) {                                            
    CardLayout card = (CardLayout) displaypanel.getLayout();
    card.show(displaypanel, "viewclientscard");
}                                           

private void viewclientspanel1MouseClicked(java.awt.event.MouseEvent evt) {
    //viewclientspanel1.getComponentListeners();
}


/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(mainframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(mainframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(mainframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(mainframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new mainframe().setVisible(true);
        }
    });
}
// Variables declaration - do not modify
private javax.swing.JMenuItem addclient;
private addclientpanel addclientpanel1;
private clientdetails clientdetails1;
private javax.swing.JMenu clients;
private javax.swing.JScrollPane displayScrollPane;
private javax.swing.JPanel displaypanel;
private javax.swing.JMenuBar mainmenu;
private javax.swing.JMenu transactions;
private javax.swing.JMenuItem viewclients;
private viewclientspanel viewclientspanel1;
// End of variables declaration
}

The class of the card that displays a list of the clients to choose from has a mouse event listener which gets the value of the client selected and switches the the next card

private void jPanel1MouseClicked(java.awt.event.MouseEvent evt) {
   CardLayout card = (CardLayout) jPanel1.getParent().getParent().getParent().getParent().getLayout();
   card.show(jPanel1.getParent().getParent().getParent().getParent(), "clientdetailscard");

}

Lastly the class that I need to transfer the client selected information to which dsiplays the more details.

  public class clientdetails extends javax.swing.JPanel {


public clientdetails() {

    initComponents();
}

public static void main(String [] args) { 
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(addclient.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(addclient.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(addclient.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(addclient.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    JFrame f = new JFrame("Window"); 
    f.add(new clientdetails()); 
    f.setSize(500, 700); 
    f.setVisible(true); 
} 

private javax.swing.JPanel jPanel1;


}

回答1:

You could pass the client information from one pane to the other using setters/getters...

clientDetailsPane.setClient(clientListPanel.getClient());
// Switch panels...

I was also thinking that you could use some kind of model or Map, but that is probably overkill for what you want to achieve...

回答2:

Thanks a lot guys, I ended up using a class container to hold the variables I need transferred.

public class varcontainer {

    public String variablename;

    private static varcontainer instance = null;

    public static varcontainer getInstance(){
    if(instance == null){
        instance = new varcontainer();
    }
        return instance;
    }

}

I then call the getInstance from another class to get the current instance of the container and access the variables

varcontainer.getInstance().variablename

Thanks again for the feedback, I appreciate it.

来源：https://stackoverflow.com/questions/14514912/how-do-i-pass-data-between-cards-in-java-cardlayout

标签

java

swing

cardlayout