Solved

How to use ImageIcon

Posted on 1999-01-14
8
568 Views
Last Modified: 2012-05-04
I have the following code


    public void actionPerformed(ActionEvent event) {
        try {
        if (en) {
                String file1 = "file:///c:/jdk1.2/sources/dk/des/lal/test1.jpg";

            URL url = new URL(file1);
            ImageIcon icon = new ImageIcon(url);

          button.setIcon(icon);
            button.repaint();
            button.validate();
            en = false;
        }
        else {
                String file2 = "file:///c:/jdk1.2/sources/dk/des/lal/test2.jpg";

            URL url = new URL(file2);
            ImageIcon icon = new ImageIcon(url);

            button.setIcon(icon);
            button.repaint();
            button.validate();

          en = true;
        }
        } catch (MalformedURLException mue) {
            mue.printStackTrace();
        } catch (java.io.IOException ioe) {
            ioe.printStackTrace();
        }
    }


When I run this it loads the two images just fine, but if I change one of the images it does not register this in my button...

Is it some sort of cache, and how do I avoid it ?
0
Comment
Question by:marss
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 3
8 Comments
 
LVL 16

Expert Comment

by:heyhey_
ID: 1230994

I don't understand quite well your problem.
When you change one of the .jpeg files and what code do you use to set the new image to your button ?

or you have tried this code
 String file1 = "file:///c:/jdk1.2/sources/dk/des/lal/test1.jpg";
 URL url = new URL(file1);
 ImageIcon icon = new ImageIcon(url);
 button.setIcon(icon);
again, and it does not show the new .jpeg version on the button ?

also what is your platform / JDK version / Swing version

regards
  heyhey
0
 

Author Comment

by:marss
ID: 1230995
I'll try to explain...

I'm trying to change the image on a JButton dynamically.
At the start I load some image x from a URL, then at some point I want to change the image on the JButton to a new image.
BUT the path must not change.

I'll change the actual data of the image by replacing the file on the harddisk.

 * copy x to harddisk (path file:///test.jpg)
 * load image into button
 * copy y to harddisk (path file:///test.jpg)
 * load image into button

I hope this makes sense :-)

thanx
0
 
LVL 16

Expert Comment

by:heyhey_
ID: 1230996
is this application or applet ?
if this is applet, browser may perform some sort of caching which is not accessible for your Java applet.
if you are making application, than this effect should be quite easy to implement.

I can build (and test) a small example if you describe your target platform.


0
Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

 

Author Comment

by:marss
ID: 1230997
It is an application.

JDK1.2 (final)
WinNT4.0

And yes it should be quite easy... :-)
0
 
LVL 16

Expert Comment

by:heyhey_
ID: 1230998
try this code for loading new Icon. I don't think that Java will cache reading from file (although it probably will cache reading from URL)

String file1 = "file:///c:/jdk1.2/sources/dk/des/lal/test1.jpg";
Image img = Toolit.getDefalutToolkit().createImage(file1);
ImageIcon icon = newImageIcon(img);
button.setIcon(icon);

0
 
LVL 16

Expert Comment

by:heyhey_
ID: 1230999
of course you need real file name :(

String file1 = c:/jdk1.2/sources/dk/des/lal/test1.jpg";
0
 

Author Comment

by:marss
ID: 1231000
It worked ....

thanx a bunch
0
 
LVL 16

Accepted Solution

by:
heyhey_ earned 200 total points
ID: 1231001
so i'm posting an answer ;)
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

By the end of 1980s, object oriented programming using languages like C++, Simula69 and ObjectPascal gained momentum. It looked like programmers finally found the perfect language. C++ successfully combined the object oriented principles of Simula w…
This was posted to the Netbeans forum a Feb, 2010 and I also sent it to Verisign. Who didn't help much in my struggles to get my application signed. ------------------------- Start The idea here is to target your cell phones with the correct…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
The viewer will learn how to implement Singleton Design Pattern in Java.

733 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question