Question

我正在创建一个类似于幻灯片放映的小型应用程序，我需要知道我该怎么做，以便在图标数组中，图像具有最大尺寸并且不会占据所有内容，因为它们无法正确显示

public class Frame extends JFrame {

    private JLabel slidesLabel = new JLabel();
    private Icon[] icons;
    private int currentSlide = -1;

    public Frame() {
        try {
            // Personally, I'd use File#listFiles to list all the
            // images in a directory, but that might be consider
            // using our initiative...

            icons = new Icon[]{
                    new ImageIcon(ImageIO.read(new File("src/WordToImage/img/prueba.png"))),
                    new ImageIcon(ImageIO.read(new File("src/WordToImage/img/prueba-2.png"))),
                    new ImageIcon(ImageIO.read(new File("src/WordToImage/img/prueba.png")))
            };
            Dimension max = new Dimension(300,600);
            slidesLabel.setMaximumSize(max);
            slidesLabel.setVerticalAlignment(JLabel.CENTER);
            slidesLabel.setHorizontalAlignment(JLabel.CENTER);
            setLayout(new BorderLayout());

            add(slidesLabel, BorderLayout.CENTER);
            slidesLabel.addMouseListener(new ClickListener());
            nextSlide();

        } catch (IOException exp) {
            exp.printStackTrace();
        }
    }

    public void nextSlide() {
        if (currentSlide < icons.length - 1) {
            currentSlide++;
            slidesLabel.setIcon(icons[currentSlide]);
        }
    }

    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) {
                    ex.printStackTrace();
                }

                Frame frame = new Frame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ClickListener extends MouseAdapter {

        @Override
        public void mouseClicked(MouseEvent e) {
            nextSlide();
        }
    }

}

问题在于图像的格式不合适，无法占据整个面板，难以辨认，而且很恐怖。

非常感谢您的帮助。

如果可能的话，我也想添加一些箭头而不是点击。

编辑：

这是应用程序中的图像 This is the image in the app

这是原始图像 This is the original image

Answer 1

请找到用于在带有预览图标的jframe中加载jpg文件的示例代码。

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.net.MalformedURLException;
import java.util.List;

import javax.swing.AbstractAction;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JToolBar;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;

public class IconicImage2 extends JFrame {

    private JLabel photographLabel = new JLabel();
    private JToolBar buttonBar = new JToolBar();

    private String imagedir = "images/icons/";

    /**
     * List of all the descriptions of the image files. These correspond one to one
     * with the image file names
     */
    private String[] imageCaptions = { "Original SUNW Logo", "The Clocktower", "Clocktower from the West",
            "The Mansion", "Sun Auditorium" };

    /**
     * List of all the image files to load.
     */
    private String[] imageFileNames = { "1.jpg", "2.jpg", "3.jpg", "4.jpg" };

    /**
     * Main entry point to the demo. Loads the Swing elements on the "Event Dispatch
     * Thread".
     *
     * @param args
     */
    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                IconicImage2 app = new IconicImage2();
                app.setSize(new Dimension(800, 600));
                app.setVisible(true);
            }
        });
    }

    /**
     * Default constructor for the demo.
     */
    public IconicImage2() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("Icon Demo: Please Select an Image");

        // A label for displaying the pictures
        photographLabel.setVerticalTextPosition(JLabel.BOTTOM);
        photographLabel.setHorizontalTextPosition(JLabel.CENTER);
        photographLabel.setHorizontalAlignment(JLabel.CENTER);
        photographLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
        JScrollPane scrollPane = new JScrollPane(photographLabel);
        setPreferredSize(new Dimension(450, 110));

        // We add two glue components. Later in process() we will add thumbnail buttons
        // to the toolbar inbetween thease glue compoents. This will center the
        // buttons in the toolbar.
        buttonBar.add(Box.createGlue());
        buttonBar.add(Box.createGlue());

        add(buttonBar, BorderLayout.SOUTH);
        add(scrollPane, BorderLayout.CENTER);

        setSize(400, 300);

        // this centers the frame on the screen
        setLocationRelativeTo(null);

        // start the image loading SwingWorker in a background thread
        loadimages.execute();
    }

    /**
     * SwingWorker class that loads the images a background thread and calls publish
     * when a new one is ready to be displayed.
     *
     * We use Void as the first SwingWroker param as we do not need to return
     * anything from doInBackground().
     */
    private SwingWorker<Void, ThumbnailAction> loadimages = new SwingWorker<Void, ThumbnailAction>() {

        /**
         * Creates full size and thumbnail versions of the target image files.
         */
        @Override
        protected Void doInBackground() throws Exception {
            for (int i = 0; i < imageCaptions.length; i++) {
                ImageIcon icon;
                icon = createImageIcon(imagedir + imageFileNames[i], imageCaptions[i]);

                ThumbnailAction thumbAction = null;
                if (icon != null) {

                    ImageIcon thumbnailIcon = new ImageIcon(getScaledImage(icon.getImage(), 32, 32));

                    thumbAction = new ThumbnailAction(icon, thumbnailIcon, imageCaptions[i]);

                }
                if (thumbAction != null)
                    publish(thumbAction);
            }
            // unfortunately we must return something, and only null is valid to
            // return when the return type is void.
            return null;
        }

        /**
         * Process all loaded images.
         */
        @Override
        protected void process(List<ThumbnailAction> chunks) {
            for (ThumbnailAction thumbAction : chunks) {
                JButton thumbButton = new JButton(thumbAction);
                // add the new button BEFORE the last glue
                // this centers the buttons in the toolbar
                buttonBar.add(thumbButton, buttonBar.getComponentCount() - 1);
            }
        }
    };

    /**
     * Creates an ImageIcon if the path is valid.
     * 
     * @param String
     *            - resource path
     * @param String
     *            - description of the file
     * @throws MalformedURLException 
     */
    protected ImageIcon createImageIcon(String path, String description) throws MalformedURLException {
//      java.net.URL imgURL = new java.net.URL(path);
        if (path != null) {
            return new ImageIcon(path, description);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    /**
     * Resizes an image using a Graphics2D object backed by a BufferedImage.
     * 
     * @param srcImg
     *            - source image to scale
     * @param w
     *            - desired width
     * @param h
     *            - desired height
     * @return - the new resized image
     */
    private Image getScaledImage(Image srcImg, int w, int h) {
        BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = resizedImg.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g2.drawImage(srcImg, 0, 0, w, h, null);
        g2.dispose();
        return resizedImg;
    }

    /**
     * Action class that shows the image specified in it's constructor.
     */
    private class ThumbnailAction extends AbstractAction {

        /**
         * The icon if the full image we want to display.
         */
        private Icon displayPhoto;

        /**
         * @param Icon
         *            - The full size photo to show in the button.
         * @param Icon
         *            - The thumbnail to show in the button.
         * @param String
         *            - The descriptioon of the icon.
         */
        public ThumbnailAction(Icon photo, Icon thumb, String desc) {
            displayPhoto = photo;

            // The short description becomes the tooltip of a button.
            putValue(SHORT_DESCRIPTION, desc);

            // The LARGE_ICON_KEY is the key for setting the
            // icon when an Action is applied to a button.
            putValue(LARGE_ICON_KEY, thumb);
        }

        /**
         * Shows the full image in the main area and sets the application title.
         */
        public void actionPerformed(ActionEvent e) {
            photographLabel.setIcon(displayPhoto);
            setTitle("Icon Demo: " + getValue(SHORT_DESCRIPTION).toString());
        }
    }
}

参考

请通过以下链接显示缩略图图标程序的示例。

https://docs.oracle.com/javase/tutorial/uiswing/components/icon.html

转到“更复杂的图像图标示例”部分
请参考程序“ IconDemoApp.java”
或按jnlp启动按钮观看演示。

调整大小图标

1 个答案: