Java GUI小程序之图片浏览器

以下是一个简单的图片浏览器示例代码，它包含了图片放大缩小、拖拽、上一张/下一张查看等功能。你可以根据它进行扩展，提高用户体验。

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.SwingConstants;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;public class ImageViewer extends JFrame {private static final long serialVersionUID = 1L;private JLabel imageLabel;private JScrollPane scrollPane;private BufferedImage image;private Dimension imageSize;private JPanel controlPanel;private JSlider zoomSlider;private JButton previousButton;private JButton nextButton;private int currentImageIndex = 0;private String[] imagePaths = {"image1.jpg", "image2.jpg", "image3.jpg"};private int zoomLevel = 100; // Default zoom levelpublic ImageViewer() {setTitle("Image Viewer");setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setPreferredSize(new Dimension(800, 600));setLayout(new BorderLayout());// Create image label and scroll paneimageLabel = new JLabel();imageLabel.setHorizontalAlignment(SwingConstants.CENTER);scrollPane = new JScrollPane(imageLabel);add(scrollPane, BorderLayout.CENTER);// Create control panelcontrolPanel = new JPanel();controlPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));add(controlPanel, BorderLayout.SOUTH);// Create zoom sliderzoomSlider = new JSlider(SwingConstants.HORIZONTAL, 50, 200, zoomLevel);zoomSlider.setMajorTickSpacing(50);zoomSlider.setMinorTickSpacing(10);zoomSlider.setPaintTicks(true);zoomSlider.setPaintLabels(true);zoomSlider.addChangeListener(new ChangeListener() {public void stateChanged(ChangeEvent e) {zoomLevel = zoomSlider.getValue();updateImage();}});controlPanel.add(zoomSlider);// Create previous buttonpreviousButton = new JButton("Previous");previousButton.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {if (currentImageIndex > 0) {currentImageIndex--;loadImage();}}});controlPanel.add(previousButton);// Create next buttonnextButton = new JButton("Next");nextButton.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {if (currentImageIndex < imagePaths.length - 1) {currentImageIndex++;loadImage();}}});controlPanel.add(nextButton);// Load the first imageloadImage();// Add mouse listeners to enable draggingimageLabel.addMouseListener(new MouseAdapter() {public void mousePressed(MouseEvent e) {imageLabel.setCursor(new java.awt.Cursor(java.awt.Cursor.MOVE_CURSOR));}public void mouseReleased(MouseEvent e) {imageLabel.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));}});imageLabel.addMouseMotionListener(new MouseMotionAdapter() {public void mouseDragged(MouseEvent e) {int dx = e.getX() - (imageSize.width - scrollPane.getViewport().getWidth()) / 2;int dy = e.getY() - (imageSize.height - scrollPane.getViewport().getHeight()) / 2;int newHValue = scrollPane.getHorizontalScrollBar().getValue() - dx;int newVValue = scrollPane.getVerticalScrollBar().getValue() - dy;if (newHValue < 0)newHValue = 0;if (newVValue < 0)newVValue = 0;if (newHValue + scrollPane.getViewport().getWidth() > imageSize.width)newHValue = imageSize.width - scrollPane.getViewport().getWidth();if (newVValue + scrollPane.getViewport().getHeight() > imageSize.height)newVValue = imageSize.height - scrollPane.getViewport().getHeight();scrollPane.getHorizontalScrollBar().setValue(newHValue);scrollPane.getVerticalScrollBar().setValue(newVValue);}});pack();setLocationRelativeTo(null);setVisible(true);}private void loadImage() {try {image = ImageIO.read(new File(imagePaths[currentImageIndex]));imageSize = new Dimension(image.getWidth(), image.getHeight());updateImage();} catch (IOException e) {JOptionPane.showMessageDialog(this, "Error loading image: " + e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);}}private void updateImage() {int newWidth = (int) (imageSize.width * zoomLevel / 100.0);int newHeight = (int) (imageSize.height * zoomLevel / 100.0);BufferedImage scaledImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);scaledImage.getGraphics().drawImage(image, 0, 0, newWidth, newHeight, null);imageLabel.setIcon(new ImageIcon(scaledImage));}public static void main(String[] args) {try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());} catch (Exception e) {// Ignore}new ImageViewer();}}

运行效果如下：