在Action中啓用Jbutton監聽器

Question

我面臨一個問題。我在java中創建了一個註冊表單，其中包含3個按鈕.LogIn，SignUp和Place order，其中包含setEnabled（False）。我想在loginframe中包含id和psw，在用戶提供正確的id和psw系統後，PlaceOrder按鈕被啓用。我如何管理它;

主框架類

public class MainFrame extends JFrame{ 

     private JButton loginButton; 
     private JButton signUpButton; 
     JButton placeOrderButton; 

     private boolean q; 

     private UserManager userManager; 

     public MainFrame(){ 
      super("Main Panel"); 
      userManager = new UserManager(); 
      loginButton = new JButton("Login"); 
      loginButton.addActionListener(new LoginButtonListener()); 
      placeOrderButton = new JButton("Place Order"); 
      placeOrderButton.addActionListener(new PlaceOrderButtonListener()); 
      placeOrderButton.setEnabled(false); 



      signUpButton = new JButton("Sign Up"); 
      signUpButton.addActionListener(new SignUpButtonListener()); 



      this.getContentPane().add(loginButton, BorderLayout.LINE_START); 
      this.getContentPane().add(signUpButton, BorderLayout.CENTER); 
      this.getContentPane().add(placeOrderButton, BorderLayout.LINE_END); 
      this.pack(); 
      this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
      this.setVisible(true); 






     } 

     class LoginButtonListener implements ActionListener{ 

      @Override 

      public void actionPerformed(ActionEvent arg0) { 
       new LoginFrame(userManager); 

      } 
     } 

     class SignUpButtonListener implements ActionListener{ 

      @Override 
      public void actionPerformed(ActionEvent arg0) { 
       new SignUpFrame(userManager); 
      } 
     } 


     class PlaceOrderButtonListener implements ActionListener { 

      public void actionPerformed(ActionEvent argO){ 



      } 


     } 

LoginFrame類

public class LoginFrame extends JFrame{ 

    private JButton loginButton; 
    private JTextField usernameField; 
    private JPasswordField password; 

    private UserManager userManager; 

    public LoginFrame(UserManager userManager){ 
     super("Enter your credentials to login"); 
     this.userManager = userManager; 
     loginButton = new JButton("Login"); 
     loginButton.addActionListener(new LoginButtonListener()); 

     usernameField = new JTextField(15); 
     password = new JPasswordField(15); 

     JPanel mainPanel = new JPanel(); 
     mainPanel.setLayout(new GridLayout(3,2)); 

     mainPanel.add(new JLabel("Username:")); 
     mainPanel.add(usernameField); 
     mainPanel.add(new JLabel("Password:")); 
     mainPanel.add(password); 
     mainPanel.add(loginButton); 

     this.setContentPane(mainPanel); 
     this.pack(); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     this.setVisible(true); 
    }   
     class LoginButtonListener implements ActionListener{ 


public void actionPerformed(ActionEvent arg0) { 
    String givenID = usernameField.getText(); 



    if(userManager.isUserInList(givenID)){ 
     String givenPass = password.getText(); 
     User theUser = userManager.getUserWithID(givenID); 
     if(givenPass.equals(theUser.getPassword())){ 
      dispose(); 

      JOptionPane.showMessageDialog(null, "Access granted!"); 


     } 


     else{ 
      JOptionPane.showMessageDialog(null, 
          "Wrong Password", 
          "Error!", 
          JOptionPane.ERROR_MESSAGE); 
     } 
    } 
    else{ 
     JOptionPane.showMessageDialog(null, 
       "Wrong username", 
       "Error!", 
       JOptionPane.ERROR_MESSAGE); 
    } 
} 

}

類的UserManager

import java.util.ArrayList; 


public class UserManager { 

    private ArrayList<User> userList; 

    public UserManager(){ 
     userList = new ArrayList<User>(); 
     User u1 = new User("Teo Haik", "teo@uom.gr","teohaik","teopass"); 
     userList.add(u1); 
    } 

    public boolean isUserInList(String ID){ 
     for(User u: userList){ 
      if(u.getUserID().equals(ID)){ 
       return true; 
      } 
     } 
     return false; 
    } 

    public User getUserWithID(String ID){ 
     for(User u: userList){ 
      if(u.getUserID().equals(ID)){ 
       return u; 
      } 
     } 
     return null; 
    } 

    public void addUser(User p){ 
     if(!userList.contains(p)){ 
      userList.add(p); 
     } 
    } 
} 

Answer 1

我無法理解你的代碼，這裏到處是工作乾淨的代碼：希望它可以幫助

使用爲先導

package stackoverflow; 

import java.awt.EventQueue; 

public class Login { 

    private JFrame frame; 
    private JTextField txtusername; 
    private JPasswordField txtPassword; 
    private JButton btnPlaceorder; 

    /** 
    * Launch the application. 
    */ 
    public static void main(String[] args) { 
     EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       try { 
        Login window = new Login(); 
        window.frame.setVisible(true); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
     }); 
    } 

    /** 
    * Create the application. 
    */ 
    public Login() { 
     initialize(); 
    } 

    /** 
    * Initialize the contents of the frame. 
    */ 
    private void initialize() { 
     frame = new JFrame(); 
     frame.setBounds(100, 100, 341, 240); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().setLayout(null); 

     JLabel lblUsername = new JLabel("Username:"); 
     lblUsername.setBounds(21, 56, 52, 14); 
     frame.getContentPane().add(lblUsername); 

     JLabel lblPassword = new JLabel("Password"); 
     lblPassword.setBounds(21, 94, 52, 14); 
     frame.getContentPane().add(lblPassword); 

     txtusername = new JTextField(); 
     txtusername.setBounds(83, 53, 86, 20); 
     frame.getContentPane().add(txtusername); 
     txtusername.setColumns(10); 

     txtPassword = new JPasswordField(); 
     txtPassword.setColumns(10); 
     txtPassword.setBounds(83, 91, 86, 20); 
     frame.getContentPane().add(txtPassword); 

     JButton btnNewButton = new JButton("Login"); 
     btnNewButton.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       if (txtusername.getText().equals("admin") && new String(txtPassword.getPassword()).equals("admin")) { 
        btnPlaceorder.setEnabled(true); 
       } else { 
        btnPlaceorder.setEnabled(false); 
       } 
      } 
     }); 
     btnNewButton.setBounds(10, 138, 89, 23); 
     frame.getContentPane().add(btnNewButton); 

     btnPlaceorder = new JButton("PlaceOrder"); 
     btnPlaceorder.setEnabled(false); 
     btnPlaceorder.setBounds(105, 138, 89, 23); 
     frame.getContentPane().add(btnPlaceorder); 
    } 
} 

Answer 2

這裏現已全面工作代碼：

我已經做了一個修復，但是你的代碼寫得不好。我更新了一些像密碼檢查之類的東西來測試。

主框架類

import java.awt.BorderLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

import javax.swing.JButton; 
import javax.swing.JFrame; 

public class MainFrame extends JFrame { 

    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 
    private JButton loginButton; 
    private JButton signUpButton; 
    private JButton placeOrderButton; 

    private boolean q; 

    private UserManager userManager; 
    private LoginFrame loginFrame; 

    public MainFrame() { 
     super("Main Panel"); 
     userManager = new UserManager(); 
     loginButton = new JButton("Login"); 
     loginButton.addActionListener(new LoginButtonListener()); 
     placeOrderButton = new JButton("Place Order"); 
     placeOrderButton.addActionListener(new PlaceOrderButtonListener()); 
     placeOrderButton.setEnabled(false); 

     signUpButton = new JButton("Sign Up"); 
     signUpButton.addActionListener(new SignUpButtonListener()); 

     this.getContentPane().add(loginButton, BorderLayout.LINE_START); 
     this.getContentPane().add(signUpButton, BorderLayout.CENTER); 
     this.getContentPane().add(placeOrderButton, BorderLayout.LINE_END); 
     this.pack(); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     loginFrame = new LoginFrame(this); 
     this.setVisible(true); 

    } 

    public void enableOrder() { 
     this.placeOrderButton.setEnabled(true); 
    } 

    class LoginButtonListener implements ActionListener { 

     @Override 
     public void actionPerformed(ActionEvent arg0) { 
      loginFrame.init(userManager); 

     } 
    } 

    class SignUpButtonListener implements ActionListener { 

     @Override 
     public void actionPerformed(ActionEvent arg0) { 
      // new SignUpFrame(userManager); 
     } 
    } 

    class PlaceOrderButtonListener implements ActionListener { 

     public void actionPerformed(ActionEvent argO) { 

     } 

    } 
} 

登入畫面

import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JPasswordField; 
import javax.swing.JTextField; 

public class LoginFrame extends JFrame { 

    private JButton loginButton; 
    private JTextField usernameField; 
    private JPasswordField password; 

    private UserManager userManager; 
    private MainFrame mainFrame; 

    public LoginFrame(MainFrame mainFrame) { 
     super("Enter your credentials to login"); 
     this.mainFrame = mainFrame; 

    } 

    public void init(UserManager userManager) { 
     loginButton = new JButton("Login"); 
     loginButton.addActionListener(new LoginButtonListener()); 

     usernameField = new JTextField(15); 
     password = new JPasswordField(15); 

     JPanel mainPanel = new JPanel(); 
     mainPanel.setLayout(new GridLayout(3, 2)); 

     mainPanel.add(new JLabel("Username:")); 
     mainPanel.add(usernameField); 
     mainPanel.add(new JLabel("Password:")); 
     mainPanel.add(password); 
     mainPanel.add(loginButton); 
     this.userManager = userManager; 
     this.setContentPane(mainPanel); 
     this.pack(); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     this.setVisible(true); 
    } 

    class LoginButtonListener implements ActionListener { 

     public void actionPerformed(ActionEvent arg0) { 
      String givenID = usernameField.getText(); 

      if (userManager.isUserInList(givenID)) { 
       String givenPass = new String(password.getPassword()); 
       User theUser = userManager.getUserWithID(givenID); 
       if (givenPass.equals("password")) { 

        dispose(); 

        JOptionPane.showMessageDialog(null, "Access granted!"); 
        mainFrame.enableOrder(); 

       } 

       else { 
        JOptionPane.showMessageDialog(null, "Wrong Password", "Error!", JOptionPane.ERROR_MESSAGE); 
       } 
      } else { 
       JOptionPane.showMessageDialog(null, "Wrong username", "Error!", JOptionPane.ERROR_MESSAGE); 
      } 
     } 
    } 

}