JFrame does not refresh after deleting an image
I'm working for the first t开发者_运维问答ime with images in a JFrame, and I have some problems. I succeeded in putting an image on my JFrame, and now i want after 2 seconds to remove my image from the JFrame. But after 2 seconds, the image does not disappear, unless I resize the frame or i minimize and after that maximize the frame. Help me if you can. Thanks.
Here is the code:
File f = new File("2.jpg");
System.out.println("Picture " + f.getAbsolutePath()); BufferedImage image = ImageIO.read(f); MyBufferedImage img = new MyBufferedImage(image); img.resize(400, 300); img.setSize(400, 300); img.setLocation(50, 50); getContentPane().add(img);
this.setSize(600, 400); this.setLocationRelativeTo(null); this.setVisible(true);
Thread.sleep(2000); System.out.println("2 seconds over");
getContentPane().remove(img);
Here is the MyBufferedImage class:
public class MyBufferedImage extends JComponent{
private BufferedImage image;
private int nPaint;
private int avgTime;
private long previousSecondsTime;
public MyBufferedImage(BufferedImage b) {
super();
this.image = b;
this.nPaint = 0;
this.avgTime = 0;
this.previousSecondsTime = System.currentTimeMillis();
}
@Override
public void paintComponent(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.setColor(Color.BLACK);
g2D.fillRect(0, 0, this.getWidth(), this.getHeight());
long currentTimeA = System.currentTimeMillis();
//g2D.drawImage(this.image, 320, 0, 0, 240, 0, 0, 640, 480, null);
g2D.drawImage(image, 0,0, null);
long currentTimeB = System.currentTimeMillis();
this.avgTime += currentTimeB - currentTimeA;
this.nPaint++;
if (currentTimeB - this.previousSecondsTime > 1000) {
System.out.format("Drawn FPS: %d\n", nPaint++);
System.out.format("Average time of drawings in the last sec.: %.1f ms\n", (double) this.avgTime / this.nPaint++);
this.previousSecondsTime = currentTimeB;
this.avgTime = 0;
this.nPaint = 0;
}
}
}
just call this.repaint()
after removing the image and all will be well ;)
You probably need to invalidate the frame component forcing a redraw.
Probably your best bet is to look at the update/repaint methods.
Have you tried calling
getContentPane().revalidate() ;
after the call to remove?
You should ensure that you are removing your image from your component in the Event Dispatch Thread. Give this a try:
SwingUtilities.invokeLater(new Runnable() {
public void run() {
getContentPane().remove(img);
}
}
Your img
will either need to be a global or declared final
in local scope for this to work. Take a look at concepts on Swing Threads if you are not already familiar.
Note: The remove
call on Container
will call invalidate()
if the content pane is considered valid.
Give
SwingUtilities.updateComponentTreeUI(this);
a Shot
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