Question

我正在开发一个Java Swing项目，我希望页面顶部有JMenuBar JMenu s，当我选择JMenu时，我想要JFrame 1}}填充一些输入字段。我尝试将构成框架的面板添加到JMenu，当我按下每个JMenu时，JFrame由不同的组件填充。我的问题是，我可以用不同的方式得到这个结果吗？

Answer 1

对于JFrame，JMenu栏的场景，其中每个菜单适用于不同的视图/面板......

您应该考虑使用CardLayout

在jframe中将jmenu放在顶部
使用Parent JPanel
将此JPanel指定为CardLayout。

将每个JPanel添加为卡片中的卡片

cards.add（card1，“Card 1”）;

cards.add（card2，“Card 2”）;

cards.add（card3，“Card 3”）;

在每个菜单上，单击切换到所需的面板：按

CardLayout cardLayout = (CardLayout) cards.getLayout();
cardLayout.show(cards, "Card 2");

Answer 2

这是Maverick_Mrt写的一个很小的例子：

package test;

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;


public class CardTest extends JFrame {

public CardTest() {
    super("Card Test");
    this.getContentPane().setLayout(new BorderLayout());

    JMenuBar menuBar = new JMenuBar();
    JMenu cardsMenu = new JMenu("Cards");
    JMenuItem card1 = new JMenuItem("Card 1");
    JMenuItem card2 = new JMenuItem("Card 2");

    cardsMenu.add(card1);
    cardsMenu.add(card2);

    menuBar.add(cardsMenu);
    this.getContentPane().add(menuBar, BorderLayout.NORTH);

    JPanel cardPanel1 = new JPanel();
    cardPanel1.setLayout(new BorderLayout());
    cardPanel1.add(new JLabel("Card_ 1"), BorderLayout.CENTER);

    JPanel cardPanel2 = new JPanel();
    cardPanel2.setLayout(new BorderLayout());
    cardPanel2.add(new JLabel("Card_ 2"), BorderLayout.CENTER);

    JPanel cards = new JPanel();
    cards.setLayout(new CardLayout());

    cards.add(cardPanel1, "Card 1");
    cards.add(cardPanel2, "Card 2");

    card1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            CardLayout cardLayout = (CardLayout) cards.getLayout();
            cardLayout.show(cards, "Card 1");
        }
    });

    card2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            CardLayout cardLayout = (CardLayout) cards.getLayout();
            cardLayout.show(cards, "Card 2");
        }
    });
    this.getContentPane().add(cards,BorderLayout.CENTER);

    this.setDefaultCloseOperation(EXIT_ON_CLOSE);        
    this.pack();
    this.setVisible(true);        
}
public static void main(String args[]) {
    CardTest cardTest = new CardTest();
}

}

当我按下JMenu时，如何用组件填充JFrame？

2 个答案: