JTextField JPasswordField

Question

编写程序，利用JTextField和JPasswordField分别接收用户输入的用户名和密码，并对用户输入的密码进行检验。对于每个用户名有3次密码输入机会。 提示：ActionEvent事件的处理接口为ActionListener,需要重写的方法名为actionPerformed

Answer 1

import java.awt.EventQueue;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
import java.awt.BorderLayout;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JTextField;
import java.awt.Color;
import javax.swing.JCheckBox;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import javax.swing.JTextPane;
import java.awt.TextArea;
import java.awt.Label;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;
 
public class test {
 
    private JFrame frame;
    private JPasswordField passwordField;
    private JTextField textField;
 
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    test window = new test();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
 
    /**
     * Create the application.
     */
    public test() {
        initialize();
         
    }
    /**
     * Judge the pwd and username
     */
    public void judge() {
         
    }
 
    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);
         
 
        Label label_2 = new Label("login");//login
        label_2.setBounds(141, 31, 139, 23);
        frame.getContentPane().add(label_2);
         
         
        JButton btnNewButton = new JButton("\u767B\u5F55");//登录
        btnNewButton.setBounds(168, 198, 93, 23);
        btnNewButton.setBackground(Color.LIGHT_GRAY);
        btnNewButton.addActionListener(new ActionListener() {
            int i = 3;
            public void actionPerformed(ActionEvent arg0) {
                String usr=textField.getText();
                String pwd=passwordField.getText();
                 
                while(i!=0) {
                    i--;
                    if(usr.equals("123456")&pwd.equals("abc123")) {
                        JOptionPane.showMessageDialog(null,  "登陆成功！欢迎徐小白同学~");
                        break;
                     }
                    else {
                        JOptionPane.showMessageDialog(null, "账户或密码错误，你还有"+(i)+"次机会");
                        break;
                    }
                }
                if(i==0) {
                    System.exit(0);
                }
            }
        });
        frame.getContentPane().add(btnNewButton);
         
        Label label = new Label("\u5B66\u53F7\uFF1A");//学号
        label.setBounds(140, 73, 34, 23);
        frame.getContentPane().add(label);
         
        Label label_1 = new Label("\u5BC6\u7801\uFF1A");//密码
        label_1.setBounds(140, 121, 34, 23);
        frame.getContentPane().add(label_1);
         
        passwordField = new JPasswordField();
        passwordField.setBounds(182, 123, 79, 21);
        frame.getContentPane().add(passwordField);
 
        textField = new JTextField();
        textField.setBounds(182, 73, 79, 21);
        frame.getContentPane().add(textField);
        textField.setColumns(10);
         
    }
     
}