創建選定的序列或內部類

Question

我想為每個按鈕創建一個選擇序列或創建一個內部類，以處理每個按鈕的事件單擊。 我的任務是單擊一個按鈕以顯示在文本框中，或標記在界面中單擊的按鈕。

到目前為止，我制作了六個按鈕和兩個面板（每個面板中三個按鈕）。 我仍在努力進行內部學習。 我不確定如何使用ActionListener和ActionPerformed。 我需要使內部類在文本框中顯示所選按鈕的幫助。 謝謝！

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

public class PracticeEventDriven extends JFrame {

    public PracticeEventDriven()
    {
    JButton firstButton = new JButton("Button 1");
    JButton secondButton = new JButton("Button 2");
    JButton thirdButton = new JButton("Button 3");
    JButton fourthButton = new JButton("Button 4");
    JButton fifthButton = new JButton("Button 5");
    JButton sixthButton = new JButton("Button 6"); 

    /*Something is wrong with this. I want to use Button 4 to display.*/

    ActionListener listener = new ActionListener();
    fourthButton.addActionListener(listener);

        JPanel group1 = new JPanel();
        setLayout(new FlowLayout());

        group1.add(firstButton);
        group1.add(secondButton);
        group1.add(thirdButton);        

        JPanel group2 = new JPanel();
        setLayout(new FlowLayout());
        group2.add(fourthButton);
        group2.add(fifthButton);
        group2.add(sixthButton);

        this.getContentPane().add(group1);
        this.getContentPane().add(group2);


    }

    public static void main(String[] args)
    {
        PracticeEventDriven frame = new PracticeEventDriven();
        frame.setTitle("Button Panel Example");
        frame.setSize(600, 85);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

    }
}

Answer 1

為此，您需要在按鈕上使用ActionListener 。 閱讀有關ActionListener的教程，並閱讀oracle文檔 。 我已經更改了您的代碼，請對其進行檢查：

public class PracticeEventDriven extends JFrame {

    private JTextField field;

    public PracticeEventDriven() {
        field = new JTextField(10);
        JButton firstButton = new JButton("Button 1");
        JButton secondButton = new JButton("Button 2");
        JButton thirdButton = new JButton("Button 3");
        JButton fourthButton = new JButton("Button 4");
        JButton fifthButton = new JButton("Button 5");
        JButton sixthButton = new JButton("Button 6");

        ActionListener listener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                JButton b = (JButton) arg0.getSource();
                field.setText(b.getText());
            }
        };
        firstButton.addActionListener(listener);
        secondButton.addActionListener(listener);
        thirdButton.addActionListener(listener);
        fifthButton.addActionListener(listener);
        fourthButton.addActionListener(listener);
        sixthButton.addActionListener(listener);

        JPanel group1 = new JPanel();
        setLayout(new FlowLayout());

        group1.add(firstButton);
        group1.add(secondButton);
        group1.add(thirdButton);

        JPanel group2 = new JPanel();
        setLayout(new FlowLayout());
        group2.add(fourthButton);
        group2.add(fifthButton);
        group2.add(sixthButton);

        this.getContentPane().add(group1);
        this.getContentPane().add(group2);
        this.getContentPane().add(field);
    }

    public static void main(String[] args) {
        PracticeEventDriven frame = new PracticeEventDriven();
        frame.setTitle("Button Panel Example");
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);

    }
}