Swing JPasswordField類

JPasswordField類是一個專門處理密碼功能並允許編輯單行文本的組件。

類聲明

以下是javax.swing.JPasswordField類的聲明 -

public class JPasswordField
   extends JTextField

類構造函數

類方法

方法繼承

該類繼承以下類中的方法 -

• javax.swing.JTextField
• javax.swing.text.JTextComponent
• javax.swing.JComponent
• java.awt.Container
• java.awt.Component
• java.lang.Object

JPasswordField示例

使用編輯器創建以下Java程式 -

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JPasswordFieldExample {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public JPasswordFieldExample(){
      prepareGUI();
   }
   public static void main(String[] args){
       JPasswordFieldExample  swingControlDemo = new JPasswordFieldExample();
      swingControlDemo.showPasswordFieldDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java Swing JPasswordField示例");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }
      });
      headerLabel = new JLabel("", JLabel.CENTER);
      statusLabel = new JLabel("",JLabel.CENTER);
      statusLabel.setSize(350,100);

      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);
   }
   private void showPasswordFieldDemo(){
      headerLabel.setText("Control in action: JPasswordField");

      JLabel namelabel= new JLabel("用戶名: ", JLabel.RIGHT);
      JLabel passwordLabel = new JLabel("密碼", JLabel.CENTER);
      final JTextField userText = new JTextField(6);
      final JPasswordField passwordText = new JPasswordField(6);
      passwordText.setEchoChar('~');

      JButton loginButton = new JButton("登錄");
      loginButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            String data = "用戶名：" + userText.getText();
            data += ", 密碼: " + new String(passwordText.getPassword());
            statusLabel.setText(data);
         }
      });
      controlPanel.add(namelabel);
      controlPanel.add(userText);
      controlPanel.add(passwordLabel);
      controlPanel.add(passwordText);
      controlPanel.add(loginButton);
      mainFrame.setVisible(true);
   }
}

執行上面示例代碼，得到以下結果：