如何将文本字段上星号的确切数量显示为按下的数字，而不是在按下 enter 时添加额外的星号？

Question

我现在的问题是如何显示文本字段中星号的确切数量与按下的数字的数量而不添加额外的星号？因为每当我按下回车按钮时，它都会在文本字段上继续添加另一个星号。我一直在尝试我应该放在哪里以及放什么以避免在我按下回车按钮时添加额外的星号

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.*;

public class Pincode extends JPanel implements ActionListener {
JLabel display, displayExtra;
JButton numButton;
JButton clr;
JButton etr;
String displayContent = "";
String[] numPadContent = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "CLEAR", "0", "ENTER"};
ArrayList<JButton> buttonList;
String PINCODE = "061904";
JFrame f;
Pincode(Container pane) {
    pane.setPreferredSize(new Dimension(320, 335));
    display = new JLabel(displayContent);
    displayExtra = new JLabel(displayContent);
    display.setPreferredSize(new Dimension(320, 30));
    display.setBorder(BorderFactory.createLoweredBevelBorder());
    pane.add(display, BorderLayout.PAGE_START);
    buttonList = new ArrayList<JButton>(12);
    JPanel numberPanel = new JPanel();
    numberPanel.setLayout(new GridLayout(4, 3, 0, 0));
    numberPanel.setPreferredSize(new Dimension(320, 260));
    for (int i = 0; i < numPadContent.length; i++) {
        numButton = new JButton(numPadContent[i]);
        buttonList.add(numButton);
    }
    for (int n = 0; n < buttonList.size(); n++) {
        buttonList.get(n).addActionListener(this);
        numberPanel.add(buttonList.get(n));
    }
    pane.add(numberPanel, BorderLayout.LINE_END);
    clr = new JButton("Clear");
    clr.setPreferredSize(new Dimension(160, 30));
    clr.addActionListener(this);
    etr = new JButton("Enter");
    etr.setPreferredSize(new Dimension(160, 30));
    etr.addActionListener(this);
    pane.add(clr);
    pane.add(etr);
}
public void Authorized(){
    JOptionPane.showMessageDialog(f,"You are authorized");
}
public void Unauthorized(){
    JOptionPane.showMessageDialog(f,"You are not authorized!!!");
}
public void actionPerformed(ActionEvent e) {
    String textThere = display.getText(), textThereExtra = displayExtra.getText();
    String additionalText = "";
    for (int a = 0; a < buttonList.size(); a++) {
        if (e.getSource().equals(buttonList.get(a)) && a!=11 && a!=9) {
            additionalText = buttonList.get(a).getText();
        }
    }
    int flag = 0;
    if (e.getSource().equals(buttonList.get(9))) {
        textThere = "";
        textThereExtra = "";
        flag = 1;
    }
    if(flag!=1) {
        display.setText(textThere.concat("*"));
        displayExtra.setText(textThereExtra.concat(additionalText));
    }
    else
    {
        display.setText(textThere);
        displayExtra.setText(textThereExtra);
    }

    if (e.getSource().equals(buttonList.get(11))) {
        System.out.println(textThereExtra);
        System.out.println(textThere);
        if(textThereExtra.equals(PINCODE)) {
            Authorized();
        }
        else {
            Unauthorized();
        }
    }

}

public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(new Pincode(frame));
    frame.pack();
    frame.setVisible(true);
}
}

请帮助我编写代码。非常感谢！

Answer 1

如果您不打算为每个按钮制作匿名类，那么您应该查看 ActionEvent

的 actionCommand

public void actionPerformed(ActionEvent e) {
    String textThere = display.getText(), textThereExtra = displayExtra.getText();
    String additionalText = "";

    if ("Enter".equalsIgnoreCase(e.getActionCommand())) {
        System.out.println(textThereExtra);
        System.out.println(textThere);
        if (textThereExtra.equals(PINCODE)) {
            Authorized();
        } else {
            Unauthorized();
        }
    } else if ("Clear".equalsIgnoreCase(e.getActionCommand())) {
        textThere = "";
        textThereExtra = "";
        display.setText("");
        displayExtra.setText("");
    } else {
        for (int a = 0; a < buttonList.size(); a++) {
            if (e.getSource().equals(buttonList.get(a)) && a != 11 && a != 9) {
                additionalText = buttonList.get(a).getText();
            }
        }
        display.setText(textThere.concat("*"));
        displayExtra.setText(textThereExtra.concat(additionalText));
    }
}

nb：这是对您的代码的快速修改，它可能不是 100% 满足您的需求，但应该让您朝着正确的方向前进

如何将文本字段上星号的确切数量显示为按下的数字，而不是在按下 enter 时添加额外的星号？

How do you show the exact number of asterisk on the textfield to the numbers pressed and not add an additional asterisk when enter is pressed?

java

swing

awt