Re: Drawing an Image in a JPanel

From:
"Andrew Thompson" <andrewthommo@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
30 Aug 2006 02:30:58 -0700
Message-ID:
<1156930258.357173.193390@h48g2000cwc.googlegroups.com>
john wrote:

I'm using Netbeans GUI and wrote the following code to draw an Image in
a JPanel. It works fine until I switch windows and then the image is
gone.

I am aware to the paint function but I don't know how to make sure to
redraw the image inside the JPanel. I do want to be able to target it
to the JPanel borders.


What does 'target it to the JPanel borders' mean?

Does it mean that you want the image to fill the
JPanel with no border around it?
....

Here is my code, ImageCrop_Panel is a JPanel created with the GUI tool

 private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {


'jButton2' is an extremely poor name for a button.

        this.jFrame1.setVisible(false);


ditto 'jFrame1'.

If all else fails, use a name that *describes* them.

         Graphics g = this.ImageCrop_Panel.getGraphics();
          g.drawImage( img1, 0, 0, this );

    }


The mechanism you are using to paint the image is
fundamentally broken, you should override paint()
or paintComponent() for reliable behaviour (this is probably
the fundamental cause of the vanishing graphic).

In Swing components, you override paintComponent() rather
than paint() (as you might with AWT).

Alternately, putting an image in a JLabel and adding the
JLabel to the GUI is a far easier way to get an image
on-screen.

HTH

Andrew T.

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