我正在创建一个哑巴手机（就像旧的传统手机），我正在使用GUI编程。拨打号码我需要帮助。我不知道如何在显示屏上弹出数字并保持在那里，并且还使用删除按钮删除显示屏上的数字。我将发布一个youtube链接，以便您可以看到示例运行。
我目前停留在传递应该显示数字的每个数字的按钮上的文本，但它显示按钮的文本。我也不知道如何在没有重置按钮的情况下按下其他按钮时保持数字。
这是我的代码：
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import javax.swing.*;
public class DumbPhone extends JFrame
{
private static final long serialVersionUID = 1L;
private static final int WIDTH = 300;
private static final int HEIGHT = 500;
private static final String CALL_BUTTON_TEXT = "Call";
private static final String TEXT_BUTTON_TEXT = "Text";
private static final String DELETE_BUTTON_TEXT = "Delete";
private static final String CANCEL_BUTTON_TEXT = "Cancel";
private static final String SEND_BUTTON_TEXT = "Send";
private static final String END_BUTTON_TEXT = "End";
private static final String CALLING_DISPLAY_TEXT = "Calling...";
private static final String TEXT_DISPLAY_TEXT = "Enter text...";
private static final String ENTER_NUMBER_TEXT = "Enter a number...";
private JTextArea display;
private JButton topMiddleButton;
private JButton topLeftButton;
private JButton topRightButton;
private JButton[] numberButtons;
private JButton starButton;
private JButton poundButton;
private boolean isNumberMode = true;
private String lastPressed = "";
private int lastCharacterIndex = 0;
private Date lastPressTime;
public DumbPhone()
{
setTitle("Dumb Phone");
setSize(WIDTH, HEIGHT);
setDefaultCloseOperation(EXIT_ON_CLOSE);
createContents();
setVisible(true);
topLeftButton.setEnabled(false);
}
private void createContents()
{
//create JPanel, and JTextArea display
JPanel panel = new JPanel(new GridLayout(5,3));
display = new JTextArea();
display.setPreferredSize(new Dimension(280, 80));
display.setFont(new Font("Helvetica", Font.PLAIN, 32));
display.setLineWrap(true);
display.setEnabled(false);
panel.add(display);
//create JButtons
topLeftButton = new JButton(DELETE_BUTTON_TEXT);
topMiddleButton = new JButton((CALL_BUTTON_TEXT));
topRightButton = new JButton((TEXT_BUTTON_TEXT));
numberButtons = new JButton[10];
numberButtons[1] = new JButton("<html><center>1<br></center></html>");
numberButtons[2] = new JButton("<html><center>2<br>ABC</center></html>");
numberButtons[3] = new JButton("<html><right>3<br>DEF</right></html>");
numberButtons[4] = new JButton("<html><center>4<br>GHI</center></html>");
numberButtons[5] = new JButton("<html><center>5<br>JKL</center></html>");
numberButtons[6] = new JButton("<html><center>6<br>MNO</center></html>");
numberButtons[7] = new JButton("<html><center>7<br>PQRS</center></html>");
numberButtons[8] = new JButton("<html><center>8<br>TUV</center></html>");
numberButtons[9] = new JButton("<html><center>9<br>WXYZ</center></html>");
numberButtons[0] = new JButton("<html><center>0<br>space</center></html>");
poundButton = new JButton("#");
starButton = new JButton("*");
//add JButtons to buttons JPanel
panel.add(topLeftButton);
panel.add(topMiddleButton);
panel.add(topRightButton);
panel.add(numberButtons[1]);
panel.add(numberButtons[2]);
panel.add(numberButtons[3]);
panel.add(numberButtons[4]);
panel.add(numberButtons[5]);
panel.add(numberButtons[6]);
panel.add(numberButtons[7]);
panel.add(numberButtons[8]);
panel.add(numberButtons[9]);
panel.add(starButton);
panel.add(numberButtons[0]);
panel.add(poundButton);
//add Listener instance (inner class) to buttons
topLeftButton.addActionListener(new Listener());
topMiddleButton.addActionListener(new Listener());
topRightButton.addActionListener(new Listener());
//JButton[] array = new JButton[10];
for (int i = 0; i < numberButtons.length; i++)
{
numberButtons[i].addActionListener(new Listener());
numberButtons[i] = new JButton(String.valueOf(i));
}
starButton.addActionListener(new Listener());
poundButton.addActionListener(new Listener());
//add display and buttons to JFrame
setLayout(new BorderLayout());
add(display, BorderLayout.NORTH);
add(panel, BorderLayout.CENTER);
}
private class Listener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == topLeftButton)
{
if(lastPressTime == null)
{
display.setText(ENTER_NUMBER_TEXT);
}
else
{
topLeftButton.setEnabled(true);
lastCharacterIndex--;
lastPressed = lastPressTime.toString();
}
}
else if(e.getSource() == topMiddleButton)
{
if(lastPressTime == null || lastCharacterIndex == 0)
{
display.setText(ENTER_NUMBER_TEXT);
}
else
{
display.setText(CALLING_DISPLAY_TEXT);
}
}
else if(e.getSource() == topRightButton)
{
if(lastPressTime == null || lastCharacterIndex == 0)
{
display.setText(TEXT_DISPLAY_TEXT);
}
else
{
display.setText(CALLING_DISPLAY_TEXT);
}
}
else
{
topLeftButton.setEnabled(true);
if (e.getSource() instanceof JButton)
{
//String text = ((JButton) e.getSource()).getText();
display.setText(lastPressed + " f" + numberButtons[lastCharacterIndex].getText());
}
}
Date currentPress = new Date();
long currentTime = currentPress.getTime();
if(lastPressTime != null)
{
//long lastPressTime = lastPressTime.getTime();
//subtract lastPressTime from currentPress time to find amount of time elapsed since last button pressed.
}
lastPressTime = currentPress;
String buttonLetters = ""; // Parse Letter from button (e.g "abc").
//update lastCharacterIndex.
lastCharacterIndex++;
lastCharacterIndex = lastCharacterIndex % buttonLetters.length();
}
}
例如，如果我按下按钮2，而不是给我“2”，它会给我<html> <center> 2 ABC </ center> </ html>
因此，我需要帮助
以下是样本运行的链接：https://www.youtube.com/watch?v=evmGWlMSqqg&feature=youtu.be
尝试启动视频20秒。
要删除该号码，您可以使用labelname.setText（“”）
在基本级别，您只需要与UI分开维护“数字”。这通常被称为“模型”。该模型独立于UI，允许模型根据应用程序的需要以任意数量的方式表示。
在您的情况下，您可以使用链接列表，数组或其他一些简单的基于顺序的列表，但最简单的可能是使用StringBuilder，因为它提供了您需要的功能（追加和删除），并且可以非常简单地制作String。
因此，您需要做的第一件事是创建一个模型实例作为实例级别字段;
private StringBuilder numbers = new StringBuilder(10);
这将允许在类的实例中的任何位置访问缓冲区。
然后你需要更新模型......
else
{
topLeftButton.setEnabled(true);
if (e.getSource() instanceof JButton)
{
String text = numberButtons[lastCharacterIndex].getText();
numbers.append(text);
}
}
要删除最后一个字符，您只需使用类似...
if (numbers.length() > 0) {
numbers.deleteCharAt(numbers.length() - 1);
}
然后，当您需要时，使用类似的东西更新UI ...
display.setText(numbers.toString());
现在，这只是基本概念，您需要将这些想法应用到您的代码库中