添加密码字段 - GUI

Question

我有一个JTextField.这JTextField将用于获取用户的名称和密码.因此,如果它获取用户名,我将显示用户在"文本"字段中键入的内容.但是如果他插入密码,该字段不应显示密码(而是显示*字符).

如何让JTextField隐藏他/她键入的字符？

伪代码:

If (usernameBool!=true) {
 // Display normal text - user is able to see the password
} else {
// This is going to be a password field, so i need to not show the password to the user instead show it as ******* instead.

}

注意:我不想JPasswordField用于此

Answer 1

同样,一种可能的解决方案是使用CardLayout交换组件:

import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.*;

public class SwapFields {
   private static final String TEXT_FIELD = "text field";
   private static final String PASS_FIELD = "pass field";

   public SwapFields() {
      // TODO Auto-generated constructor stub
   }

   private static void createAndShowGui() {
      final JTextField textField = new JTextField(10);
      final JPasswordField passwordField = new JPasswordField(10);

      final CardLayout cardLayout = new CardLayout();
      final JPanel cardPanel = new JPanel(cardLayout);
      cardPanel.add(textField, TEXT_FIELD);
      cardPanel.add(passwordField, PASS_FIELD);

      JToggleButton toggleBtn = new JToggleButton("Entering Password");
      toggleBtn.addItemListener(new ItemListener() {

         @Override
         public void itemStateChanged(ItemEvent iEvt) {
            if (iEvt.getStateChange() == ItemEvent.SELECTED) {
               cardLayout.show(cardPanel, PASS_FIELD);
               passwordField.requestFocusInWindow();
            } else {
               cardLayout.show(cardPanel, TEXT_FIELD);
               textField.requestFocusInWindow();
            }
         }
      });

      JButton showNamePasswordBtn = new JButton("Show Results");
      showNamePasswordBtn.addActionListener(new ActionListener() {

         @Override
         public void actionPerformed(ActionEvent arg0) {
            System.out.println("Name: " + textField.getText());

            // never do this!
            System.out.println("Pass: " + new String(passwordField.getPassword()));
         }
      });

      JPanel mainPanel = new JPanel();
      mainPanel.add(cardPanel);
      mainPanel.add(toggleBtn);
      mainPanel.add(showNamePasswordBtn);

      JFrame frame = new JFrame("SwapFields");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

Answer 2

的JPasswordField方法为setEchoChar()。如文档所述：

设置此JPasswordField的回显字符。...设置为0表示您希望看到键入的文本，这与标准JTextField的行为类似。

然后，您可以仅使用a JPasswordField并启用'*'仅用于密码的回显字符（例如）。