java在另一个上绘制图像

Question

嘿，我正在尝试制作一个基本的启动器，对于设计，我得到了一张图片。我想让退出按钮显示在启动器图像上，以便您可以看到它。我不知道我该怎么做，所以我需要帮助。这是我的代码:

package launcher;

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
/**
 * 
 * @author Daniel <Skype: daniel.gusdal>
 *
 * Current Date: 2. feb. 2014 Current Time: 21:46:52
 * Project: 742 client. File Name: Launcher.java
 *
 */
public class Launcher extends JFrame {

    /**
     * Generated serialVersionUID
     */
    private static final long serialVersionUID = 1L;

    private JPanel contentPane;
    static Point mouseDownCompCoords;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            public void run() {
                try {
                    mouseDownCompCoords = null;
                    final Launcher frame = new Launcher();
                    frame.setResizable(true);
                    frame.setUndecorated(true);
                    frame.setBackground(new Color(0, 255, 0, 0));
                    frame.setVisible(true);
                    frame.addMouseListener(new MouseListener() {
                        public void mouseReleased(MouseEvent e) {
                            mouseDownCompCoords = null;
                        }

                        public void mousePressed(MouseEvent e) {
                            mouseDownCompCoords = e.getPoint();
                        }

                        public void mouseExited(MouseEvent e) {
                        }

                        public void mouseEntered(MouseEvent e) {
                        }

                        public void mouseClicked(MouseEvent e) {
                        }
                    });

                    frame.addMouseMotionListener(new MouseMotionListener() {
                        public void mouseMoved(MouseEvent e) {
                        }

                        public void mouseDragged(MouseEvent e) {
                            Point currCoords = e.getLocationOnScreen();
                            frame.setLocation(currCoords.x
                                    - mouseDownCompCoords.x, currCoords.y
                                    - mouseDownCompCoords.y);
                        }
                    });
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Launcher() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 841, 593);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel Design = new JLabel("New label");
        Design.setIcon(new ImageIcon(getClass().getResource("Launcher3.png")));
        Design.setBounds(-158, -22, 1047, 592);
        contentPane.add(Design);

        ImageIcon img = new ImageIcon(getClass().getResource(
                "Playnow.png"));
        final JButton Playnow = new JButton(img);
        Playnow.setBackground(null);
        Playnow.setOpaque(false);

        Playnow.addMouseListener(new MouseAdapter() {

            @Override
            public void mouseEntered(MouseEvent e) {
                Playnow.setIcon(new ImageIcon(getClass().getResource(
                        "PlaynowHover.png")));
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                Playnow.setIcon(new ImageIcon(getClass().getResource(
                        "PlaynowHover.png")));
                System.out.println(Playnow.getIcon());
            }

            @Override
            public void mouseExited(MouseEvent e) {
                Playnow.setIcon(new ImageIcon(getClass().getResource(
                        "Playnow.png")));
            }
        });

        Playnow.setBounds(258, 442, 301, 46);
        contentPane.add(Playnow);

        final JButton Exit = new JButton();
        Exit.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                System.out.println(Exit.getIcon());
                System.exit(0);
            }
        });
        Exit.setIcon(new ImageIcon(Launcher.class.getResource("Exit.png")));
        Exit.setOpaque(false);
        Exit.setBounds(766, 59, 21, 21);
        contentPane.add(Exit);
    }
}

Answer 1

1. 不要设定界限。学习使用布局管理器。

2. 在 JPanel 上绘制图像，而不是使用 JLabel

3. 将JButton 放在JPanel 上。给 JPanel 一个 GridBadLayout

4. 重写 JPanel 的 getPreferredSize()。

5. 要在图像之间切换，您可以使用像 boolean icon1, icon2, icon3; 这样的标志。并重新绘制 JPanel 和 mouseXxx。像这样

   public void mouseClicked(MouseEvent e) {
       icon1 = true;
       icon2 = false;
       icon3 = false;
       imagePanel.repaint();
   }
   ....
   protected void paintComponent(Graphics g) {
       if (icon1) {
           g.drawImage(image1, .....);
       }
       if (icon2) { ... }
       if (icon3) { ... }
   }
   

6. pack() 你的框架。

7. 使用 Java 命名约定。变量以小写字母开头。

---

举个例子

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.*;
import java.util.logging.*;
import javax.imageio.ImageIO;
import javax.swing.*;


public class TestButtonOverImage {

    public TestButtonOverImage() {
        JFrame frame = new JFrame("Test Card");
        frame.add(new ImagePanel());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                new TestButtonOverImage();
            }
        });
    }

    public class ImagePanel extends JPanel {

        BufferedImage img;

        public ImagePanel() {
            setLayout(new GridBagLayout());
            add(new JButton("StackOverflow Button"));

            try {
                img = ImageIO.read(new URL("http://d8u1nmttd4enu.cloudfront.net/designs/logo-stackoverflow-logo-design-99designs_447080~36d200d82d83d7b2e738cebd2a48de07180cef3a_largecrop"));
            } catch (MalformedURLException ex) {
                Logger.getLogger(TestButtonOverImage.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(TestButtonOverImage.class.getName()).log(Level.SEVERE, null, ex);
            }

        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 100, 100, 300, 300, this);
        }

        public Dimension getPreferredSize() {
            return new Dimension(500, 500);
        }
    }
}