編寫程序,利用JtextField和JpasswordField分別接收用戶輸入的用戶名和密碼,並對用戶輸入的密碼進行檢驗。對於每個用戶名有三次密碼輸入機會。
package beizi; 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");//登錄 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, "登陸成功!歡迎徐小白同學~"); break; } else { JOptionPane.showMessageDialog(null, "賬戶或密碼錯誤,你還有"+(i)+"次機會"); break; } } if(i==0) { System.exit(0); } } }); frame.getContentPane().add(btnNewButton); Label label = new Label("\u5B66\u53F7\uFF1A");//學號 label.setBounds(140, 73, 34, 23); frame.getContentPane().add(label); Label label_1 = new Label("\u5BC6\u7801\uFF1A");//密碼 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); } }
丑陋的效果,,,: