从当前窗口调用另一个 JFrame 窗口并交换数据

Question

我有 2 个 Swing 开发的应用程序。 1) 支付屏幕，其中会有用户 ID 和“支付”按钮。 2) 另一个屏幕将有“匹配”按钮，用于检查用户的有效性并返回相应用户的密码。

我的主屏幕是“支付”屏幕。从这里我将输入用户 ID 并单击“支付”按钮，它必须导航到“另一个屏幕”。到目前为止，我的代码正在运行。

在“匹配”按钮中进行验证后，我应该将密码返回到“支付”屏幕。这部分代码不起作用。请帮忙

 //Pay screen class
package trig_pack;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ImageIcon;
import javax.swing.JDialog;
import javax.swing.JLabel;
import java.awt.Image ;
import java.io.*; 
import java.sql.*;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import capture_match_finger_image.*;

public class trigPayClass extends javax.swing.JFrame {

    /**
     * Creates new form trigPayClass
     */
    public trigPayClass() {
        initComponents();
    }


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

        jLabel2 = new javax.swing.JLabel();
        t_userid = new javax.swing.JTextField();
        btn_pay = new javax.swing.JButton();
        lbl_result = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel2.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
        jLabel2.setHorizontalAlignment(javax.swing.SwingConstants.RIGHT);
        jLabel2.setText("User Id:");

        t_userid.setName("t_userid"); // NOI18N
        t_userid.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                t_useridActionPerformed(evt);
            }
        });

        btn_pay.setText("PAY");
        btn_pay.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btn_payActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(44, 44, 44)
                .addComponent(jLabel2)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(btn_pay)
                    .addComponent(t_userid, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(lbl_result, javax.swing.GroupLayout.PREFERRED_SIZE, 415, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(85, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(35, 35, 35)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 18, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(t_userid, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addComponent(btn_pay)
                .addGap(26, 26, 26)
                .addComponent(lbl_result, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(224, Short.MAX_VALUE))
        );

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

    private void btn_payActionPerformed(java.awt.event.ActionEvent evt) {                                        
        System.out.println("in btn_payActionPerformed");
        int v_userid=Integer.parseInt(t_userid.getText());
        System.out.println("v_userid-"+v_userid);
        Connection con=null;
                try
        {    

            con=DriverManager.getConnection(  
                         "<connection string>");  
            System.out.println("connection established..");
           fetchPasswordClass c=new fetchPasswordClass();   //another class
           String pwd=c.getpwd(v_userid,con); //call method in another class to get password fro incoming userid and connection objects
           lbl_result.setText(pwd);  //populate returned password in a label or text field. 
        } catch (Exception e) 
          { 
              e.printStackTrace(); 
          }
    }                                       

    private void t_useridActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
    }                                        

    /**
     * @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 (javax.swing.UIManager.getSystemLookAndFeelClassName().equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(trigPayClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(trigPayClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(trigPayClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(trigPayClass.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 trigPayClass().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton btn_pay;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel lbl_result;
    private javax.swing.JTextField t_userid;
    // End of variables declaration                   
}

//另一个画面

package match_pwd;

import java.awt.Color;
import java.awt.image.BufferedImage;  
import javax.swing.ImageIcon; 
import java.sql.*;
import javax.swing.JDialog; 
import javax.swing.JOptionPane;

public class fetchPasswordClass extends javax.swing.JFrame   {

    int v_userid=0;
    int v_nfiq=5;
    String match_result=null; 
    Connection i_con=null;

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

        btn_con = new javax.swing.JButton();
        pnl_srno = new javax.swing.JPanel();
        jLabel3 = new javax.swing.JLabel();
        lbl_srno = new javax.swing.JLabel();
        jLabel1 = new javax.swing.JLabel();
        lbl_nfiq = new javax.swing.JLabel();
        jPanel1 = new javax.swing.JPanel();
        lbl_fing = new javax.swing.JLabel();
        lbl_stat = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        btn_prv = new javax.swing.JButton();
        btn_match = new javax.swing.JButton();
        btn_disconn = new javax.swing.JButton();
        lbl_userid = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 
        setBackground(new java.awt.Color(130, 140, 150));
        setMinimumSize(new java.awt.Dimension(613, 389));
        setResizable(false);
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowClosing(java.awt.event.WindowEvent evt) {
                formWindowClosing(evt);
            }
            public void windowOpened(java.awt.event.WindowEvent evt) {
                formWindowOpened(evt);
            }
        });

        btn_match.setText("MATCH");
        btn_match.setEnabled(false);
        btn_match.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btn_matchActionPerformed(evt);
            }
        });


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

    private void formWindowClosing(java.awt.event.WindowEvent evt) {                                   
         //
    }                                  

    private void formWindowOpened(java.awt.event.WindowEvent evt) {                                  
        // TODO add your handling code here:
    }            

    private String btn_matchActionPerformed(java.awt.event.ActionEvent evt) {                                          
        System.out.println("In SaveActionPerformed");
        btn_match.setEnabled(false);
        if (lbl_userid.getText()!=null && lbl_userid.getText().length()>0)
        {
            System.out.println("Got Userid-"+v_userid);
            matchUserId m=new matchUserId();
            String match_success_yn=m.matchUser(v_userid);
            if (match_success_yn.equals("0"))
            { 
                match_result="Not valid user!";
            }
            else
            { 
                match_result=match_success_yn;
            }
        }
        else
        {
            System.out.println("Userid null");
            lbl_stat.setText("Please enter valid user id");
            btn_match.setEnabled(false); 
            match_result="Please pass valid user id";
        }
        return match_result;
    }                                         



    public String getpwd(int userid,Connection con){ 

        v_userid=userid; 
        System.out.println("v_userid- "+v_userid); 
        i_con=con;
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if (javax.swing.UIManager.getSystemLookAndFeelClassName().equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(fetchPasswordClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(fetchPasswordClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(fetchPasswordClass.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(fetchPasswordClass.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 fetchPasswordClass().setVisible(true); 

            initComponents();
            c.getContentPane().setBackground(new Color(176,176,176));//153, 255, 255  

            lbl_userid.setText(String.valueOf(v_userid)); 
            System.out.println(" lbl_userid.getText()- "+ lbl_userid.getText());         


             c.setVisible(true);

            }
        });
        System.out.println("before returning from matchclass");
       // return match_result; 
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton btn_con;
    private javax.swing.JButton btn_disconn;
    private javax.swing.JButton btn_match;
    private javax.swing.JButton btn_prv;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JLabel lbl_fing;
    private javax.swing.JLabel lbl_nfiq;
    private javax.swing.JLabel lbl_srno;
    private javax.swing.JLabel lbl_stat;
    private javax.swing.JLabel lbl_userid;
    private javax.swing.JPanel pnl_srno;
    // End of variables declaration                   

}

Answer 1

You need to pass data using constructors

First create a constructor inside the fetchPasswordClass

String fetchedPassword = null;
public fetchPasswordClass(String password){
 
 //then pass the value to fetchedPassword variable
 fetchedPassword = password;
 //then initialize the components
 initComponents();

}

--------------------------------

Then inside the trigPayClass inside the button action
fetchPasswordClass obj = new fetchPasswordClass(password);
obj.setVisible(true);

Answer 2

假设这是你的主窗口

public class MainWindow extends JFrame {
   private AnotherWindow another_window;

    public MainWindow() {
        init();        
        another_window = new AnotherWindow(this);
    }

    private void init() {
        //some codes for JFrame
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            new MainWindow().setVisible(true);
        });
    }

   public void your_event(/*some parameters*/) {
       another_window.setVisible(true);
       another_window.validateInfo(/*some values for the parameter*/); 
   }

}

这是另一个窗口

public class AnotherWindow extends JFrame {

    private MainWindow main_window;   

    public AnotherWindow(MainWindow main_window) {
        this.main_window = main_window;
    }

    public boolean validateInfo(/**some parameters like string password, string username**/) {
        return result;
    }

}

这背后的想法是让“对象”知道是谁打电话给他们的。 在此示例中，MainWindow 创建了一个AnotherWindow 的实例。在AnotherWindow 类中，我们为调用它的对象创建了一个参数。我们在AnotherWindow 类中声明了一个MainWindow 对象，但没有为其分配值，因为我们还不知道MainWindow 的哪个具体实例将调用AnotherWindow。