Question

我正在尝试创建和假设的ATM GUI界面，通过键盘输入几个数字。在用户单击任何按钮后，我无法让程序显示数字。我只是为了时间而创建了一个按钮：

public JButton jbtOne = new JButton(STANDARD_BTN_TEXTS[0][0]);

因此，如果用户点击了＆＃39; jbtOne＆＃39;说4次。 JTextField应该显示1111.我的问题是按钮没有响应代码行：

addActionListener(listener)

如何让JButton在JTextField中打印整数？我之前已经开始使用它了，但是在使用这行代码添加更加用户友好的外观之后，它已经无法再次工作了：

 private static final String[][] STANDARD_BTN_TEXTS = 
{
    {"1", "2", "3"},
    {"4", "5", "6"},
    {"7", "8", "9"},
    { "0" }

有人能指出我正确的方向吗？任何帮助将不胜感激！

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.JFrame;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractButton;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JPasswordField;

public class TerminalATM extends JFrame
{
private JPanel panel;
public final JPasswordField passwordField = new JPasswordField(2);
private static final String[][] STANDARD_BTN_TEXTS = 
{
    {"1", "2", "3"},
    {"4", "5", "6"},
    {"7", "8", "9"},
    { "0" }
};
private static final int GAP = 5;
private static final Font BTN_FONT = new Font(Font.DIALOG, Font.BOLD, 20);
public JButton jbtOne = new JButton(STANDARD_BTN_TEXTS[0][0]);
 private JTextField jtfNumber1 = new JTextField(8);//Define Number Field

public TerminalATM()
{       
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null); 

    JPanel standardPanel = createBtnPanel(STANDARD_BTN_TEXTS, "KeyPad");
    JPanel buttonPanel = new JPanel();
    buttonPanel.setLayout(new GridLayout(0, 1));
    buttonPanel.add(jtfNumber1, BorderLayout.NORTH);
    buttonPanel.add(standardPanel, BorderLayout.SOUTH);



    BtnListener listener = new BtnListener();
    jbtOne.addActionListener(listener);

    TextFieldHandler handler = new TextFieldHandler();
    passwordField.addActionListener(handler);

    add(buttonPanel, BorderLayout.LINE_START);
    setSize(450, 500);
    setVisible(true);
}

//Create Unique Rows of Buttons
private JPanel createBtnPanel(String[][] texts, String title) {
    JPanel btnPanel = new JPanel();
    int rows = texts.length;
    int cols = texts[0].length;
    btnPanel.setLayout(new GridLayout(rows, cols, GAP, GAP));
    for (int row = 0; row < texts.length; row++) {
        for (int col = 0; col < texts[row].length; col++) {
            JButton btn = new JButton(texts[row][col]);
            btn.setFont(BTN_FONT);
            btnPanel.add(btn);
        }
    }
    btnPanel.setBorder(BorderFactory.createTitledBorder(title));
    return btnPanel;
  }


  private class TextFieldHandler implements ActionListener
 {

  @Override
  public void actionPerformed(ActionEvent event)
  {
  String string = "";

 if(event.getSource()==passwordField)
 string = String.format("textField1: %s", event.getActionCommand());
 }
 } 

/**** Create Button Listener and Action Listener ****/
 class BtnListener implements ActionListener 
{
    @Override
 public void actionPerformed(ActionEvent e)
{
      /* This is where we would set each button to the action event */
      /* Only Button one for brevity */
   int int1=0;
 if(e.getSource().equals(jbtOne))
{
     int1 = 1;
  passwordField.setText(String.valueOf(int1));

  }
 }
 }


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

Answer 1

我认为您没有将createBtnPanel添加到可见面板中。您的createBtnPanel方法会创建自己的按钮并将其添加到面板中，而不会有任何动作侦听器。

尝试更改for (int row = 0; row < texts.length; row++) { for (int col = 0; col < texts[row].length; col++) { final String text = texts[row][col]; final JButton btn = new JButton(text); btn.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ev) { passwordField.setText(text); } }); btn.setFont(BTN_FONT); btnPanel.add(btn); } }的内部循环的以下行：

POST

如果你不明白这是做什么或有任何问题，请告诉我。

如果您使用的是Java 8，也可以大大简化此代码，但我认为您不能直接回答。

Answer 2

您的侦听器正在使用passwordField，但您似乎已在面板中添加了一个文本字段，请使用passwordField或jtfNumber1。

如何让JButton使用Action Listener和Action Event在JTextField中打印整数？

2 个答案: