java - 如何在 JFrame 中使单个 JPanel 变大

Question

我正在制作游戏，我的框架内有多个面板。 panel4 应该包含我的轮子，问题是当我需要 panel4 更大时，panel4 与板上所有其他面板的大小相同，因为我希望轮子的图片完全显示，因为它是这样的，当我需要显示所有车轮时，只有车轮的顶部显示。

 public static void setUp() throws IOException {        
    frame=new JFrame();
    frame.setLayout(new GridLayout(7,1));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocation(290, 5);
    frame.setSize(1100, 1100);
    frame.setTitle("Wheel of fortune");

    final JPanel scorePanel=new JPanel();
    final JPanel namePanel=new JPanel();
    final JPanel panel=new JPanel(new GridLayout(1,3,1,1));
    final JPanel panel1=new JPanel();
    final JPanel panel2=new JPanel();
    final JPanel panel3=new JPanel(new GridLayout(2,1,1,1));

    panel3.add(new JLabel("Dead letters/phrases:"));
    panel3.add(LettersOrPhGuessed);

    scorePanel.add(new JLabel("Score Board:"));


    final WheelGui test = new WheelGui();
    final JPanel panel4=test;
    panel4.setSize(800, 600);//this does nothing in the program


    namePanel.add(playerName);
    frame.getContentPane().add(namePanel);
    frame.getContentPane().add(scorePanel);
    frame.getContentPane().add(panel);
    frame.getContentPane().add(panel4);
    frame.getContentPane().add(panel2);
    frame.getContentPane().add(panel1);
    frame.getContentPane().add(panel3);
    frame.setVisible(true);
}

这就是我构造 panel4 本质的地方。我试图让这个面板变大，但当我这样做时，屏幕上似乎没有任何反应。任何建议都会很棒。

@SuppressWarnings("serial")
public class WheelGui extends JPanel{
ImageIcon image = new ImageIcon("WheelofFortune.JPG");    
JPanel rotationPanel;  
final int WIDTH = 800;  
final int HEIGHT = 600;  
static double degrees;  

public WheelGui()  
{  
    super();
    this.setPreferredSize(new Dimension(WIDTH,HEIGHT));  
    setBackground(Color.lightGray);  
    setLayout(null);  
    setFocusable(true);  
    rotationPanel = new JPanel(); 

    rotationPanel = new turningCanvas();  
    rotationPanel.setPreferredSize(new Dimension(image.getIconWidth(),image.getIconHeight()));  
    //rotationPanel.setSize(800,600);  
    add(rotationPanel);  
    rotationPanel.setBounds(WIDTH/8, HEIGHT/8, rotationPanel.getPreferredSize().width, rotationPanel.getPreferredSize().height);  
    degrees = 0;  
}  
public void paintComponent (Graphics g)  
{  
    super.paintComponent(g);  
}  
public class turningCanvas extends JPanel  
{  
    public void paintComponent (Graphics g)  
    {  
        super.paintComponent(g);  
        Graphics2D g2d = (Graphics2D)g;  
        g2d.rotate(Math.toRadians(degrees),image.getIconWidth()/2,image.getIconHeight()/2);  
        image.paintIcon(this, g2d, 0, 0);  

    }  
}   
public void rotate(){
    for(int i=0;i<360;i+=4){
        degrees++;
        repaint();
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

Answer 1

你有很多问题......

首先，您正在使用 GridLayout。 GridLayout 将以网格模式布局所有组件，并根据父容器的宽度和高度为每个组件分配相同数量的空间。如果您希望组件具有不同的大小，GridLayout 不是最佳选择。

其次，您正在使用 setPreferredSize。这是一种不好的做法，因为您没有防范应用程序的其他部分稍后可能会尝试更改组件的大小。

相反，您应该尽可能覆盖 getPreferredSize 方法。

就我个人而言，我会推荐 GridBagLayout，但您可能需要查看 A Visual Guide to Layout Managers其他选择

用例子更新

我知道的唯一方法是使用 GridBagLayout，它使您可以灵活地定义各个组件将从可用空间中占用多少空间。它是最灵活和最难掌握的布局管理器之一......

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;

public class TestLayout25 {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }
                try {
                    setUp();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        });
    }

    public static void setUp() throws IOException {
        JFrame frame = new JFrame();
        frame.setLayout(new GridBagLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);
        frame.setLocationRelativeTo(null);
        frame.setTitle("Wheel of fortune");

        final JPanel scorePanel = new JPanel();
        final JPanel namePanel = new JPanel();
        final JPanel panel = new JPanel(new GridLayout(1, 3, 1, 1));
        final JPanel panel1 = new JPanel();
        final JPanel panel2 = new JPanel();
        final JPanel panel3 = new JPanel(new GridLayout(2, 1, 1, 1));

        panel3.add(new JLabel("Dead letters/phrases:"));
        panel3.add(createPane(Color.RED));

        scorePanel.add(new JLabel("Score Board:"));


        final WheelGui test = new WheelGui();
        final JPanel panel4 = test;
        panel4.setSize(800, 600);//this does nothing in the program

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        gbc.weightx = 1;
        gbc.fill = GridBagConstraints.HORIZONTAL;

        namePanel.add(new JLabel("Blue"), gbc);
        frame.getContentPane().add(namePanel, gbc);
        frame.getContentPane().add(scorePanel, gbc);
        frame.getContentPane().add(panel, gbc);
        gbc.weighty = 1;
        gbc.fill = GridBagConstraints.BOTH;
        frame.getContentPane().add(panel4, gbc);
        gbc.weighty = 0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        frame.getContentPane().add(panel2, gbc);
        frame.getContentPane().add(panel1, gbc);
        frame.getContentPane().add(panel3, gbc);
        frame.setVisible(true);
    }

    protected static JPanel createPane(Color color) {

        JPanel panel = new JPanel();
        panel.setBorder(new LineBorder(color));
        return panel;

    }

    public static class WheelGui extends JPanel {

        ImageIcon image = new ImageIcon("WheelofFortune.JPG");
        JPanel rotationPanel;
        final int WIDTH = 800;
        final int HEIGHT = 600;
        static double degrees;

        public WheelGui() {
            super();
            this.setPreferredSize(new Dimension(WIDTH, HEIGHT));
            setBackground(Color.lightGray);
            setLayout(null);
            setFocusable(true);
            rotationPanel = new JPanel();

            rotationPanel = new turningCanvas();
            rotationPanel.setPreferredSize(new Dimension(image.getIconWidth(), image.getIconHeight()));
            //rotationPanel.setSize(800,600);  
            add(rotationPanel);
            rotationPanel.setBounds(WIDTH / 8, HEIGHT / 8, rotationPanel.getPreferredSize().width, rotationPanel.getPreferredSize().height);
            degrees = 0;
        }

        public void paintComponent(Graphics g) {
            super.paintComponent(g);
        }

        public class turningCanvas extends JPanel {

            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = (Graphics2D) g;
                g2d.rotate(Math.toRadians(degrees), image.getIconWidth() / 2, image.getIconHeight() / 2);
                image.paintIcon(this, g2d, 0, 0);

            }
        }

        public void rotate() {
            for (int i = 0; i < 360; i += 4) {
                degrees++;
                repaint();
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}