Question

我试图制作一个可以添加姓名和地址的程序。我试图使用GridLayout，但没有按钮显示。我在这做错了什么？感谢

您好。我正在尝试制作一个可以添加姓名和地址的程序。我试图使用GridLayout，但没有按钮显示。我在这做错了什么？感谢

import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;


public class AddressBookProgram extends JFrame {

    public AddressBookProgram() {
        super("Test");   
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setContentPane(new GridPanel());
        setSize(300, 300);
        setVisible(true);
    }

    private final class GridPanel extends JPanel {
        private JPanel bookPanel;
        private JPanel buttonPanel;
        private JButton add;
        private JButton delete;
        private JButton search;
        private JButton displayAll;
        private JButton exit;
        private ActionListener buttons = new ButtonListener();


        private GridPanel() {
            setLayout(new GridLayout(2, 3));
            setBackground(Color.green);

            bookPanel = new JPanel();
            bookPanel.setBackground(Color.white);
            buttonPanel = new JPanel();
            buttonPanel.setBackground(Color.white);

            add = new JButton("Add");
            delete = new JButton("Delete");
            search = new JButton("Search");
            displayAll = new JButton("Display All");
            exit = new JButton("Exit");

            add.addActionListener(buttons);
            delete.addActionListener(buttons);
            search.addActionListener(buttons);
            displayAll.addActionListener(buttons);
            exit.addActionListener(buttons);

            buttonPanel.add(add);
            buttonPanel.add(delete);
            buttonPanel.add(search);
            buttonPanel.add(displayAll);
            buttonPanel.add(exit);
        }


        private class ButtonListener implements ActionListener {

            /**
             * <p>Updates the watchLabel label when button is pushed.</p>
             * @param event a button is pushed
             */
            public void actionPerformed(ActionEvent event) {
                if (event.getSource() == add) {
                }

                if (event.getSource() == delete) {
                }

                if (event.getSource() == search) {
                }

                if (event.getSource() == displayAll) {
                }

                if (event.getSource() == exit) {
                }
            }         
        }


    }
    public static void main(String[] args) {
        new AddressBookProgram();
    }   
}

Answer 1

这是因为您创建 buttonPanel，但不添加。只需写下这一行：

add(buttonPanel);

这将使您的代码成为：

buttonPanel.add(add);
buttonPanel.add(delete);
buttonPanel.add(search);
buttonPanel.add(displayAll);
buttonPanel.add(exit);

add(buttonPanel);

Java没有按钮显示

1 个答案: