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我目前正在Netbeans中工作一個簡單的項目，習慣JFrame表單。我創建了幾個JFrames，我想通過按下按鈕跳過它們，但每當按下按鈕時都不會發生任何事情。JFrame中的JButton不起作用
這是我的代碼
public class MainLogIn extends javax.swing.JFrame {
/**
* Creates new form MainLogIn
*/
//testdata
private String[] dummy_data = {"user1:parola1", "user2:parola2"};
public MainLogIn() {
initComponents();
LogIn = new JButton();
signUp = new JButton();
username = new JTextField();
password = new JPasswordField();
wrong = new JLabel();
wrong.setVisible(false);
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
username = new javax.swing.JTextField();
password = new javax.swing.JPasswordField();
LogIn = new javax.swing.JButton();
signUp = new javax.swing.JButton();
wrong = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("Username:");
jLabel2.setText("Password:");
LogIn.setText("LogIn");
LogIn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
LogInActionPerformed(evt);
}
});
signUp.setText("SignUp");
signUp.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
signUpActionPerformed(evt);
}
});
wrong.setText("Wrong Username And Password");
wrong.setVisible(false);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(16, 16, 16)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGap(31, 31, 31)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(username, javax.swing.GroupLayout.DEFAULT_SIZE, 120, Short.MAX_VALUE)
.addComponent(password)))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addComponent(LogIn)
.addGap(95, 95, 95)
.addComponent(signUp))
.addGroup(layout.createSequentialGroup()
.addGap(60, 60, 60)
.addComponent(wrong)))
.addContainerGap(146, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(51, 51, 51)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(username, javax.swing.GroupLayout.PREFERRED_SIZE, 35, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 27, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(password, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(52, 52, 52)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(LogIn)
.addComponent(signUp))
.addGap(26, 26, 26)
.addComponent(wrong)
.addContainerGap(48, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private boolean isPasswordValid(String password)
{
if(password.length()>8)
return true;
else
return false;
}
private boolean loginAttempt(String user, String pass){
String usertext, passtext;
//get username and password
usertext = user;
passtext = pass;
//check username
if(usertext == null)
{
username.setText("Please add username");
}
if(passtext == null)
{
password.setText("Please add password");
}
else
if(isPasswordValid(passtext) == false)
password.setText("Password too short");
//check for good data among dummy_data
for(String credentials:dummy_data)
{
String[] user_pass = credentials.split(":");
if(user_pass[0].equals(usertext) &&
user_pass[1].equals(passtext))
{
return true;
}
}
return false;
}
private void LogInActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String usertext, passtext;
usertext = username.getText().toString();
passtext = password.getText().toString();
if(loginAttempt(usertext,passtext) == true)
{
LogIn.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent ae) {
WelcomeToTheServer view = new WelcomeToTheServer();
view.setVisible(true);
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
});
}
else
{
wrong.setVisible(true);
}
}
private void signUpActionPerformed(java.awt.event.ActionEvent evt) {
// start NewUser JFrame
signUp.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent ae) {
NewUser new_userjframe = new NewUser();
new_userjframe.setVisible(true);
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
});
}
/**
* @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(MainLogIn.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MainLogIn.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MainLogIn.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MainLogIn.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 MainLogIn().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton LogIn;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JPasswordField password;
private javax.swing.JButton signUp;
private javax.swing.JTextField username;
private javax.swing.JLabel wrong;
// End of variables declaration
}
當我嘗試
LogIn.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent ae) {
WelcomeToTheServer view = new WelcomeToTheServer();
view.setVisible(true);
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
});
理智最多發生。我寫錯了ActionListener嗎？
謝謝
*「我創建了幾個JFrame」* 1）使用['CardLayout']（http://download.oracle.com/javase/8/docs /api/java/awt/CardLayout.html），如[本答案]（http://stackoverflow.com/a/5786005/418556）所示。 2）請參見[多個JFrames的使用，良好/錯誤的實踐？]（http://stackoverflow.com/q/9554636/418556）3）請參見[檢測/修復代碼塊的懸掛閉合括號]（http ：//meta.stackexchange.com/q/251795/155831）對於一個問題，我不能再糾結於此。 –