选项1

Question

我正在处理一个菜单，我希望尽可能使它成为面向对象，所以我为菜单JPanel对象创建了一个单独的类。问题是它不想将它添加到我的主JPanel。我做错了什么，应该如何解决？

主要类别：

package StackOverflow;
import java.awt.CardLayout;
import javax.swing.*;

public class Main {

    private JFrame frame = new JFrame();
    private JPanel MainPanel = new JPanel();
    private CardLayout cl = new CardLayout();
    private GamePanel gp = new GamePanel();

    public Main(){
        frame.setLocation(100, 100);
        frame.setSize(1200, 700);
        frame.setTitle("Rain | Pre-Alpha");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        MainPanel.setLayout(cl);

        MainPanel.add(gp, "1");

        frame.add(MainPanel);

        cl.show(MainPanel, "1");

        frame.setVisible(true);
    }

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

GamePanel类：

package StackOverflow;
import java.awt.Color;
import javax.swing.JPanel;

public class GamePanel {
    private JPanel GamePanel = new JPanel();

    public GamePanel(){
        GamePanel.setBackground(Color.green);
    }
}

Answer 1

您无法向JFrame添加课程，JFrame接受Component：

public Component add(Component comp, int index)

所以你有很多方法可以解决你的问题：

选项1

改为JPanel：

public class GamePanel extends JPanel {

    public GamePanel() {
        super.setBackground(Color.green);
    }
}

选项2

您可以使用getter和setter：

public class GamePanel {

    private JPanel GamePanel = new JPanel();

    public JPanel getGamePanel() {
        return GamePanel;
    }

    public void setGamePanel(JPanel GamePanel) {
        this.GamePanel = GamePanel;
    }

    public GamePanel() {
        GamePanel.setBackground(Color.green);
    }

}

你可以像这样添加你的JPanel：

MainPanel.add(gp.getGamePanel(), "1");

将JPanel对象添加到单独的JPanel中

1 个答案:

选项1

选项2