Question

嗨所以我在选择单选按钮时尝试显示一个java图像，所以我使用带有if语句的代码来识别按钮输入。但我不能让图像出现。

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.Graphics;
import java.awt.Color;
    
public class Button1 extends JPanel {          
    static String sadString = "Sad Joffrey";
    static String happyString = "Happy Joffrey";
    public Button1() {                
    JRadioButton sadButton = new JRadioButton(sadString);
    sadButton.setMnemonic(KeyEvent.VK_B);
    sadButton.setActionCommand(sadString);
    sadButton.setSelected(true);
        
    JRadioButton happyButton = new JRadioButton(happyString);
    happyButton.setMnemonic(KeyEvent.VK_C);
    happyButton.setActionCommand(happyString);
        
    ButtonGroup group = new ButtonGroup();
    group.add(sadButton);
    group.add(happyButton);
    JPanel radioPanel = new JPanel(new GridLayout(0, 1));
    radioPanel.add(sadButton);
    radioPanel.add(happyButton);
    class Draw extends JComponent {
         public void paint(Graphics g) {
             if (happyButton.isSelected()) {
                 g.setColor(Color.black);
                 g.drawRect (10, 10, 200, 200);
                 g.fillOval (25, 35, 50, 50);
                 g.fillOval (150, 35, 50, 50);        
                 g.fillArc(75, 100, 100, 75, -200, 200);

             }        
        } 
    }
    add(radioPanel, BorderLayout.LINE_START);
    setBorder(BorderFactory.createEmptyBorder(30,30,300,300));
}
public static void createAndShowGUI() {
    JFrame frame = new JFrame("Button1");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    
    JComponent newContentPane = new Button1();
    newContentPane.setOpaque(true);
    frame.setContentPane(newContentPane);
    frame.pack();
    frame.setVisible(true);
    JFrame window = new JFrame();
    window.getContentPane().add(new Draw());
}       
public static void main(String[] args) {
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
    createAndShowGUI();
        }
    });
    }
}

我没有把悲伤的面孔画进去但是上面我想在if语句中显示代码，如果按下那个按钮，否则，它会显示悲伤的那个，那么我将如何绘制正确的代码？

Answer 1

我说实话，我无法关注你的代码，所以作为对自己的挑战我从头开始。这就是我想出来的......

public class Button1 extends JPanel { 

    boolean sad=false;
    boolean happy=false;

    public void paint(Graphics g) {
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, 500, 500);
        if (sad) {
            g.setColor(Color.GREEN);
            g.fillRect(10, 10, 50, 50);
        }

        if (happy) {
            g.setColor(Color.black);
            g.drawRect (10, 10, 200, 200);
            g.fillOval (25, 35, 50, 50);
            g.fillOval (150, 35, 50, 50);        
            g.fillArc(75, 100, 100, 75, -200, 200);
        }
    }


    public static void main(String[] args) {
        Button1 panel=new Button1();
        JFrame frame=new JFrame();
        frame.add(panel,BorderLayout.CENTER);
        panel.addButtons(frame);
        frame.setSize(500, 500);
        frame.setVisible(true);
    }

    private void addButtons(JFrame frame) {
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.LINE_AXIS));
        JRadioButton sadButton = new JRadioButton("Sad");
        sadButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                happy=false;
                sad=true;
                repaint();
            }
        });


        JRadioButton happyButton = new JRadioButton("Happy");
        happyButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                sad=false;
                happy=true;
                repaint();
            }
        });

        buttonPanel.add(sadButton);
        buttonPanel.add(happyButton);
        ButtonGroup group = new ButtonGroup();
        group.add(sadButton);
        group.add(happyButton);
        frame.add(buttonPanel,BorderLayout.SOUTH);
    }
}

如何使用单选按钮选择Java图形

1 个答案: