//PasswordVerification.java
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class PasswordVerification extends JFrame implements ActionListener{
JLabel userLabel; //定义用户标签提示
JLabel passwordLabel; //定义密码标签提示
JTextField userText; //定义用户文本框
JPasswordField passwordText; //定义密码文本框
int count = 1; //统计输入信息的次数 public PasswordVerification() {
super("请输入信息"); Container container =new Container(); //得到容器对象container;
container.setLayout(new FlowLayout()); //设置默认布局 userLabel = new JLabel("用户",10); //创建用户标签
passwordLabel =new JLabel("密码",10); //创建密码标签
userText = new JTextField("",10); //创建用户文本输入框
passwordText = new JPasswordField("",10); //创建密码输入文本框
passwordText.addActionListener(this); //注册事件监听者; container.add(userLabel);
container.add(userText);
container.add(passwordLabel);
container.add(passwordText);
setSize(500, 300);
setVisible(true);
} public void actionPerformed(ActionEvent e) { //事件处理
String userName = new String("陈三"); //假设为正确的用户名;
String password = new String("12345678"); //假设为正确的密码; if (e.getSource() == passwordText) {
count++;
char[] passwords = passwordText.getPassword();
if (userText.getText().equals(userName) &&
password.equals(new String(passwords))) {
JOptionPane.showMessageDialog(null, "欢迎您:" + userName);
System.exit(0);
}
else if (count > 3)
System.exit(0);
else {
JOptionPane.showMessageDialog(null, userText.getText() + "请输入正确信息");
}
}
} public static void main(String args[]) {
PasswordVerification pv = new PasswordVerification();
pv.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class PasswordVerification extends JFrame implements ActionListener{
JLabel userLabel; //定义用户标签提示
JLabel passwordLabel; //定义密码标签提示
JTextField userText; //定义用户文本框
JPasswordField passwordText; //定义密码文本框
int count = 1; //统计输入信息的次数 public PasswordVerification() {
super("请输入信息"); Container container =new Container(); //得到容器对象container;
container.setLayout(new FlowLayout()); //设置默认布局 userLabel = new JLabel("用户",10); //创建用户标签
passwordLabel =new JLabel("密码",10); //创建密码标签
userText = new JTextField("",10); //创建用户文本输入框
passwordText = new JPasswordField("",10); //创建密码输入文本框
passwordText.addActionListener(this); //注册事件监听者; container.add(userLabel);
container.add(userText);
container.add(passwordLabel);
container.add(passwordText);
setSize(500, 300);
setVisible(true);
} public void actionPerformed(ActionEvent e) { //事件处理
String userName = new String("陈三"); //假设为正确的用户名;
String password = new String("12345678"); //假设为正确的密码; if (e.getSource() == passwordText) {
count++;
char[] passwords = passwordText.getPassword();
if (userText.getText().equals(userName) &&
password.equals(new String(passwords))) {
JOptionPane.showMessageDialog(null, "欢迎您:" + userName);
System.exit(0);
}
else if (count > 3)
System.exit(0);
else {
JOptionPane.showMessageDialog(null, userText.getText() + "请输入正确信息");
}
}
} public static void main(String args[]) {
PasswordVerification pv = new PasswordVerification();
pv.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Container container =new Container(); //得到容器对象container;
换成
Container container =getContentPane(); //得到容器对象container;
就好了.//PasswordVerification.java
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class PasswordVerification extends JFrame implements ActionListener{
JLabel userLabel; //定义用户标签提示
JLabel passwordLabel; //定义密码标签提示
JTextField userText; //定义用户文本框
JPasswordField passwordText; //定义密码文本框
int count = 1; //统计输入信息的次数 public PasswordVerification() {
super("请输入信息"); Container container =getContentPane(); //得到容器对象container;
container.setLayout(new FlowLayout()); //设置默认布局 userLabel = new JLabel("用户",10); //创建用户标签
passwordLabel =new JLabel("密码",10); //创建密码标签
userText = new JTextField("",10); //创建用户文本输入框
passwordText = new JPasswordField("",10); //创建密码输入文本框
passwordText.addActionListener(this); //注册事件监听者; container.add(userLabel);
container.add(userText);
container.add(passwordLabel);
container.add(passwordText);
setSize(500, 300);
setVisible(true);
} public void actionPerformed(ActionEvent e) { //事件处理
String userName = new String("陈三"); //假设为正确的用户名;
String password = new String("12345678"); //假设为正确的密码; if (e.getSource() == passwordText) {
count++;
char[] passwords = passwordText.getPassword();
if (userText.getText().equals(userName) &&
password.equals(new String(passwords))) {
JOptionPane.showMessageDialog(null, "欢迎您:" + userName);
System.exit(0);
}
else if (count > 3)
System.exit(0);
else {
JOptionPane.showMessageDialog(null, userText.getText() + "请输入正确信息");
}
}
} public static void main(String args[]) {
PasswordVerification pv = new PasswordVerification();
pv.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}