基本上，有两种不同的BufferedImage叫做img_w和img_b1 ...... 一旦我将Jframe / label设置为其中一个，它就永远不会改变或永远不会将（）重新设置为新的Imagebuffered值......
提前致谢..
BufferedImage img_w = new BufferedImage(old_width_i, old_height_i, BufferedImage.TYPE_INT_RGB);
BufferedImage img_b1 = new BufferedImage(old_width_i, old_height_i, BufferedImage.TYPE_INT_RGB);
// add data into the img_w and img_b1
JFrame frame=new JFrame();
JLabel label = new JLabel(new ImageIcon(img_w));
frame.getContentPane().add(label, BorderLayout.WEST);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//I am trying to sleep only cause I want to make out if the image is changing or not or basically , to have a rotating illusion...
System.out.println("Hello");
frame.getContentPane().add(new JLabel(new ImageIcon(img_w)), BorderLayout.WEST);
frame.repaint();
label = new JLabel(new ImageIcon(img_b1));
frame.getContentPane().add(label,BorderLayout.WEST); //display the image (works)
label.repaint(); //update the display??
frame.repaint();
frame.getContentPane().repaint();
答案 0 :(得分：3)
此...
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
将阻止UI处理绘制请求，直到结束。你永远不应该阻止EDT。
以下示例（很简单）并演示了一种手动在图片之间移动的简单方法。
public class FlipPictures {
public static void main(String[] args) {
new FlipPictures();
}
public FlipPictures() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new PicturePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class PicturePane extends JPanel {
private JLabel picture;
private File[] pictures;
private int currentPicture = -1;
public PicturePane() {
pictures = new File("/point/me/to/a/directory/of/images").listFiles(new FileFilter() {
@Override
public boolean accept(File pathname) {
String name = pathname.getName().toLowerCase();
return name.endsWith(".png")
|| name.endsWith(".gif")
|| name.endsWith(".jpg")
|| name.endsWith(".jpeg")
|| name.endsWith(".bmp");
}
});
setLayout(new BorderLayout());
picture = new JLabel();
picture.setHorizontalAlignment(JLabel.CENTER);
picture.setVerticalAlignment(JLabel.CENTER);
add(picture);
JButton change = new JButton("Change");
add(change, BorderLayout.SOUTH);
change.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
changePicture();
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
protected void changePicture() {
if (pictures != null && pictures.length > 0) {
currentPicture++;
if (currentPicture >= pictures.length) {
currentPicture = 0;
}
try {
// This is a potentionally blocking process and really should be threaded...
picture.setIcon(new ImageIcon(ImageIO.read(pictures[currentPicture])));
picture.setText(null);
} catch (IOException ex) {
ex.printStackTrace();
picture.setText(ex.getMessage());
}
} else {
picture.setText("No Pictures :(");
}
}
}
}
<强>更新
或者如果您更喜欢在图像之间自动切换
public class FlipPictures {
public static void main(String[] args) {
new FlipPictures();
}
public FlipPictures() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new PicturePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class PicturePane extends JPanel {
private JLabel picture;
public PicturePane() {
setLayout(new BorderLayout());
picture = new JLabel();
picture.setHorizontalAlignment(JLabel.CENTER);
picture.setVerticalAlignment(JLabel.CENTER);
add(picture);
BackgroundSwitcher switcher = new BackgroundSwitcher(this);
switcher.execute();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
public void setPicture(BufferedImage image) {
picture.setIcon(new ImageIcon(image));
}
}
public class BackgroundSwitcher extends SwingWorker<Void, BufferedImage> {
private File[] pictures;
private int currentPicture = -1;
private PicturePane picturePane;
public BackgroundSwitcher(PicturePane picturePane) {
pictures = new File("/point/me/to/a/directory/of/images").listFiles(new FileFilter() {
@Override
public boolean accept(File pathname) {
String name = pathname.getName().toLowerCase();
return name.endsWith(".png")
|| name.endsWith(".gif")
|| name.endsWith(".jpg")
|| name.endsWith(".jpeg")
|| name.endsWith(".bmp");
}
});
this.picturePane = picturePane;
}
@Override
protected void process(List<BufferedImage> chunks) {
picturePane.setPicture(chunks.get(chunks.size() - 1));
}
@Override
protected Void doInBackground() throws Exception {
if (pictures != null && pictures.length > 0) {
while (true) {
currentPicture++;
if (currentPicture >= pictures.length) {
currentPicture = 0;
}
try {
publish(ImageIO.read(pictures[currentPicture]));
} catch (IOException ex) {
ex.printStackTrace();
}
Thread.sleep(1000);
}
}
return null;
}
}
}
您可能想看一下Concurrency in Swing
答案 1 :(得分：2)
您的代码不完整所以我们所能做的就是猜测。下次发布SSCCE。
我猜测问题是您正在向可见帧添加组件。您没有在面板上调用revalidate（），因此标签的大小保持为（0,0）。
但是，没有必要创建新的JLabel。只需通过调用现有标签的setIcon（）方法来更改图像，标签将自行重新绘制。无需在框架或任何其他组件上调用repaint（）。