An explanation of card layout manager in Java

This article mainly introduces the explanation and examples of Java card layout manager. Friends in need can refer to it.

The layout manager implemented by the CardLayout class is called a card layout manager and is used to manipulate the containers or components contained in the container it manages. Each container or component directly added to the container it manages is a card. The first container or component added is considered the first card, and the last one added is the last card. The first card will be displayed when running for the first time. A card. Next, let's see how it is used through an example.

Source code:

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
 

public class TestMain extends JFrame {
  private JPanel pane = null; // 主要的JPanel，该JPanel的布局管理将被设置成CardLayout
  private JPanel p = null; // 放按钮的JPanel
  private CardLayout card = null; // CardLayout布局管理器
  private JButton button_1 = null; // 上一步
  private JButton button_2 = null; // 下一步
  private JButton b_1 = null, b_2 = null, b_3 = null; // 三个可直接翻转到JPanel组件的按钮
  private JPanel p_1 = null, p_2 = null, p_3 = null; // 要切换的三个JPanel
  
  public TestMain() {
    super("CardLayout Test");
    try {
      // 将LookAndFeel设置成Windows样式
      UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
    } catch (Exception ex) {
      ex.printStackTrace();
    }
    /**创建一个具有指定的水平和垂直间隙的新卡片布局*/
    card = new CardLayout(5, 5);
    pane = new JPanel(card); // JPanel的布局管理将被设置成CardLayout
    p = new JPanel(); // 构造放按钮的JPanel
    button_1 = new JButton("< 上一步");
    button_2 = new JButton("下一步 >");
    b_1 = new JButton("1");
    b_2 = new JButton("2");
    b_3 = new JButton("3");
    b_1.setMargin(new Insets(2,2,2,2));
    b_2.setMargin(new Insets(2,2,2,2));
    b_3.setMargin(new Insets(2,2,2,2));
    p.add(button_1);
    p.add(b_1);
    p.add(b_2);
    p.add(b_3);
    p.add(button_2);
    p_1 = new JPanel();
    p_2 = new JPanel();
    p_3 = new JPanel();
    p_1.setBackground(Color.RED);
    p_2.setBackground(Color.BLUE);
    p_3.setBackground(Color.GREEN);
    p_1.add(new JLabel("JPanel_1"));
    p_2.add(new JLabel("JPanel_2"));
    p_3.add(new JLabel("JPanel_3"));
    pane.add(p_1, "p1");
    pane.add(p_2, "p2");
    pane.add(p_3, "p3");
    /**下面是翻转到卡片布局的某个组件，可参考API中的文档*/
    button_1.addActionListener(new ActionListener(){ // 上一步的按钮动作
      public void actionPerformed(ActionEvent e) {
        card.previous(pane);
      }
    });
    button_2.addActionListener(new ActionListener(){ // 下一步的按钮动作
      public void actionPerformed(ActionEvent e) {
        card.next(pane);
      }
    });
    b_1.addActionListener(new ActionListener() { // 直接翻转到p_1
      public void actionPerformed(ActionEvent e) {
        card.show(pane, "p1");
      }
    });
    b_2.addActionListener(new ActionListener() { // 直接翻转到p_2
      public void actionPerformed(ActionEvent e) {
        card.show(pane, "p2");
      }
    });
    b_3.addActionListener(new ActionListener() { // 直接翻转到p_3
      public void actionPerformed(ActionEvent e) {
        card.show(pane, "p3");
      }
    });
    this.getContentPane().add(pane);
    this.getContentPane().add(p, BorderLayout.SOUTH);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setSize(300, 200);
    this.setVisible(true);
  }
  
  public static void main(String[] args) {
    new TestMain();
  }
  
}

Note: When using the next() or previous() method to display the card , all cards will be displayed in a loop. For example, if the last card is currently displayed, calling the next() method will display the first card; if the first card is currently displayed, calling the previous() method will display the last card.

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