Java GIF 动画无法正确重画

Question

我正在尝试为 GIF 图像制作动画。动画可以，但画得不好。

它显示如下(非动画屏幕截图):

在图像中，尾部像这样摇动:

如您所见，图像重绘效果不佳。我不想使用 JLabels，但它无法正常工作，所以我遵循 this question when my image did not animate .

我的代码是这样的:

public void draw(JPanel canvas, Graphics2D g2d, int x, int y) {
    getFrontImage().paintIcon(canvas, g2d, x, y);
}

图像的检索和保存位置如下:

ImageIcon gif = new ImageIcon(getClass().getResource(filename));

在 JPanel Canvas 中，我创建了一个绘制方法和一个每 10 毫秒重新绘制一次的计时器线程。这适用于除 GIF 之外的所有内容。谁能帮我解决这个问题？

---编辑

很抱歉造成误解，我已将图像更新为我实际使用的图像。我希望得到正确的答案不会太麻烦......

Answer 1

好吧，经过一番苦思冥想，我终于能够将框架的处理方法更改为restoreToBackgroundColor。基本上，这意味着动画不是增量更改，而是完整的帧替换...

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class AnimatedGifTest1 {

    public static void main(String[] args) {
        new AnimatedGifTest1();
    }

    public AnimatedGifTest1() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new PaintPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class PaintPane extends JPanel {

        private ImageIcon image;

        public PaintPane() {
            image = new ImageIcon(getClass().getResource("/ertcM02.gif"));
            Timer timer = new Timer(40, new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    repaint();
                }
            });
            timer.start();
        }

        @Override
        public Dimension getPreferredSize() {
            return image == null ? new Dimension(200, 200) : new Dimension(image.getIconWidth(), image.getIconHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g); // This is very important!
            int x = (getWidth() - image.getIconWidth()) / 2;
            int y = (getHeight() - image.getIconHeight()) / 2;
            image.paintIcon(this, g, x, y);
        }

    }



}

已更新...

所以，我终于能够看看您正在使用的 gif 的处理方法，该方法设置为 restoreToPrevious，根据 GRAPHICS INTERCHANGE FORMAT Version 89a意思是:

Restore to previous. The decoder is required to restore the area overwritten by the graphic with what was there prior to rendering the graphic.

我上面提供的图像使用 restoreToBackgroundColor，根据 GRAPHICS INTERCHANGE FORMAT Version 89a意思是:

Restore to background color. The area used by the graphic must be restored to the background color

您可以使用以下代码自行检查...

public static class AnimatedGif {

    public enum DisposalMethod {

        RESTORE_TO_BACKGROUND,
        RESTORE_TO_PREVIOUS,
        DO_NOT_DISPOSE,
        UNSPECIFIED;

        public static DisposalMethod find(String text) {

            DisposalMethod dm = UNSPECIFIED;
            System.out.println(text);

            switch (text) {
                case "restoreToBackgroundColor":
                    dm = RESTORE_TO_BACKGROUND;
                    break;
                case "restoreToPrevious":
                    dm = RESTORE_TO_PREVIOUS;
                    break;
            }

            return dm;

        }
    }

    private List<ImageFrame> frames;
    private int frame;

    public AnimatedGif(JComponent player, URL url) throws IOException {
        frames = new ArrayList<>(25);
        try (InputStream is = url.openStream(); ImageInputStream stream = ImageIO.createImageInputStream(is)) {
            Iterator readers = ImageIO.getImageReaders(stream);
            if (!readers.hasNext()) {
                throw new RuntimeException("no image reader found");
            }
            ImageReader reader = (ImageReader) readers.next();
            reader.setInput(stream);            // don't omit this line!
            int n = reader.getNumImages(true);  // don't use false!
            System.out.println("numImages = " + n);
            for (int i = 0; i < n; i++) {
                BufferedImage image = reader.read(i);
                ImageFrame imageFrame = new ImageFrame(image);

                IIOMetadata imd = reader.getImageMetadata(i);
                Node tree = imd.getAsTree("javax_imageio_gif_image_1.0");
                NodeList children = tree.getChildNodes();

                for (int j = 0; j < children.getLength(); j++) {
                    Node nodeItem = children.item(j);
                    NamedNodeMap attr = nodeItem.getAttributes();
                    switch (nodeItem.getNodeName()) {
                        case "ImageDescriptor":
                            ImageDescriptor id = new ImageDescriptor(
                                            getIntValue(attr.getNamedItem("imageLeftPosition")),
                                            getIntValue(attr.getNamedItem("imageTopPosition")),
                                            getIntValue(attr.getNamedItem("imageWidth")),
                                            getIntValue(attr.getNamedItem("imageHeight")),
                                            getBooleanValue(attr.getNamedItem("interlaceFlag")));
                            imageFrame.setImageDescriptor(id);
                            break;
                        case "GraphicControlExtension":
                            GraphicControlExtension gc = new GraphicControlExtension(
                                            DisposalMethod.find(getNodeValue(attr.getNamedItem("disposalMethod"))),
                                            getBooleanValue(attr.getNamedItem("userInputFlag")),
                                            getBooleanValue(attr.getNamedItem("transparentColorFlag")),
                                            getIntValue(attr.getNamedItem("delayTime")) * 10,
                                            getIntValue(attr.getNamedItem("transparentColorIndex")));
                            imageFrame.setGraphicControlExtension(gc);
                            break;
                    }
                }
                frames.add(imageFrame);
            }
        } finally {
        }
    }

    protected String getNodeValue(Node node) {
        return node == null ? null : node.getNodeValue();
    }

    protected int getIntValue(Node node) {
        return node == null ? 0 : getIntValue(node.getNodeValue());
    }

    protected boolean getBooleanValue(Node node) {
        return node == null ? false : getBooleanValue(node.getNodeValue());
    }

    protected int getIntValue(String value) {
        return value == null ? 0 : Integer.parseInt(value);
    }

    protected boolean getBooleanValue(String value) {
        return value == null ? false : Boolean.parseBoolean(value);
    }

    public class ImageFrame {

        private BufferedImage image;
        private ImageDescriptor imageDescriptor;
        private GraphicControlExtension graphicControlExtension;

        public ImageFrame(BufferedImage image) {
            this.image = image;
        }

        protected void setImageDescriptor(ImageDescriptor imageDescriptor) {
            this.imageDescriptor = imageDescriptor;
        }

        protected void setGraphicControlExtension(GraphicControlExtension graphicControlExtension) {
            this.graphicControlExtension = graphicControlExtension;
            System.out.println(graphicControlExtension.getDisposalMethod());
        }

        public GraphicControlExtension getGraphicControlExtension() {
            return graphicControlExtension;
        }

        public BufferedImage getImage() {
            return image;
        }

        public ImageDescriptor getImageDescriptor() {
            return imageDescriptor;
        }

    }

    public class GraphicControlExtension {

        private DisposalMethod disposalMethod;
        private boolean userInputFlag;
        private boolean transparentColorFlag;
        private int delayTime;
        private int transparentColorIndex;

        public GraphicControlExtension(DisposalMethod disposalMethod, boolean userInputFlag, boolean transparentColorFlag, int delayTime, int transparentColorIndex) {
            this.disposalMethod = disposalMethod;
            this.userInputFlag = userInputFlag;
            this.transparentColorFlag = transparentColorFlag;
            this.delayTime = delayTime;
            this.transparentColorIndex = transparentColorIndex;
        }

        public int getDelayTime() {
            return delayTime;
        }

        public DisposalMethod getDisposalMethod() {
            return disposalMethod;
        }

        public int getTransparentColorIndex() {
            return transparentColorIndex;
        }

        public boolean isTransparentColorFlag() {
            return transparentColorFlag;
        }

        public boolean isUserInputFlag() {
            return userInputFlag;
        }

    }

    public class ImageDescriptor {

        private int imageLeftPosition;
        private int imageTopPosition;
        private int imageHeight;
        private int imageWeight;
        private boolean interlaced;

        public ImageDescriptor(int imageLeftPosition, int imageTopPosition, int imageHeight, int imageWeight, boolean interlaced) {
            this.imageLeftPosition = imageLeftPosition;
            this.imageTopPosition = imageTopPosition;
            this.imageHeight = imageHeight;
            this.imageWeight = imageWeight;
            this.interlaced = interlaced;
        }

        public int getImageHeight() {
            return imageHeight;
        }

        public int getImageLeftPosition() {
            return imageLeftPosition;
        }

        public int getImageTopPosition() {
            return imageTopPosition;
        }

        public int getImageWeight() {
            return imageWeight;
        }

        public boolean isInterlaced() {
            return interlaced;
        }

    }

}

此代码来自.gif image doesn't moves on adding it to the JTabbed pane