Question

无论我做什么，我都无法让JFrame显示任何内容。它只是空白。我将按钮starter和tutorialer添加到JPanel游戏中，并将JPanel添加到我设置为cardLayout的JPanel卡中。

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class layouter extends JFrame {
    public static void main (String[]args){
        layouter x = new layouter();
    }
    public layouter(){
        setSize(600,600);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        Pan p = new Pan();
        setContentPane(p);
        setVisible(true);

    }
}

class Pan extends JPanel{
    JButton starter;
    JButton tutorialer;
    JPanel start;
    JPanel tutorial;
    JPanel game;
    JPanel cards;
   CardLayout cl;
        Pan(){  
        starter = new JButton("start");
        tutorialer = new JButton("tutorial");
        start = new JPanel();
        tutorial = new JPanel();
        game = new JPanel();
        cards = new JPanel( new CardLayout());
        cl= (CardLayout)(cards.getLayout());
        game.setLayout(null);
        starter.setBounds(150,150,100,50);
        tutorialer.setBounds(150,200,100,50);
         game.add(starter);
        game.add(tutorialer);
        cards.add(game,"game");
        add(cards);
    repaint();
  }

public void paintComponent(Graphics g){
    super.paintComponent(g);
    cl.show(cards,"game");
    System.out.println("hello");
}

}

Answer 1

game.setLayout(null);＆lt; - 这将导致您的问题，因为您添加到此容器的任何内容都将不再自动布局。默认情况下，组件的大小和位置为0x0

使用适当的布局管理器。有关详细信息，请参阅Laying Out Components Within a Container。

如果您向games添加更多容器，则可能需要“显示”您希望首先显示的默认视图

cl.show(cards, "game");

为什么我的代码不适用于CardLayout？无论我做什么，它只显示一个空白的JFrame

1 个答案: