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Good morning

I am trying to save a awt Gui component into a file with the png
format,
I use java 1.4.0 under Solaris:
I only an empty file output for my Canvas

I used the excellent java image faq provided by Marco Schmidt
http://www.geocities.com/marcoschmidt.geo/index.html to guide me.

in the following code, the method mageIO.write() returns false
when I try to get a png file output (I only got an empty output file)
but the same works fine to get a jpeg file (nice canvas output).

Does someone has an idea why no appropriate writer is found for png
file ?

On the same computer, the Screenshot.java source works fine (from
previous Marco Schmidt url 'take a screenshot and save it to a Png
file using javax.imageio')

Thank you for your help
Ps: please reply only in the newsgroup not by email
F

Rectangle rect = getCanvas().getBounds();
Image fileImage = getCanvas().createImage(rect.width, rect.height);

Graphics g = fileImage.getGraphics();

getCanvas().paint( fileImage.getGraphics() );

try {
boolean ret = ImageIO.write((RenderedImage) fileImage, "png", new
File("map.png"));
System.out.println(ret);
} catch (IOException e1) {
/ TODO Auto-generated catch block
e1.printStackTrace();
} finally{
g.dispose();
}

F C wrote:
> Good morning
>
> I am trying to save a awt Gui component into a file with the png
> format,
> I use java 1.4.0 under Solaris:
> I only an empty file output for my Canvas
>
> I used the excellent java image faq provided by Marco Schmidt
> http://www.geocities.com/marcoschmidt.geo/index.html to guide me.
>
> in the following code, the method mageIO.write() returns false
> when I try to get a png file output (I only got an empty output file)
> but the same works fine to get a jpeg file (nice canvas output).
>
> Does someone has an idea why no appropriate writer is found for png
> file ?
>
> On the same computer, the Screenshot.java source works fine (from
> previous Marco Schmidt url 'take a screenshot and save it to a Png
> file using javax.imageio')
>
> Thank you for your help
> Ps: please reply only in the newsgroup not by email
> F
>
> Rectangle rect = getCanvas().getBounds();
> Image fileImage = getCanvas().createImage(rect.width, rect.height);
>
> Graphics g = fileImage.getGraphics();
>
> getCanvas().paint( fileImage.getGraphics() );
>
> try {
> boolean ret = ImageIO.write((RenderedImage) fileImage, "png", new
> File("map.png"));
> System.out.println(ret);
> } catch (IOException e1) {
> / TODO Auto-generated catch block
> e1.printStackTrace();
> } finally{
> g.dispose();
> }

I'm not sure why it doesn't throw and exception. Image does not support
the RenderedImage interface. You need to use a BufferedImage.

--

Knute Johnson
email s/nospam/knute/
Molon labe...

Knute Johnson <> wrote in message news:<>...

>
> I'm not sure why it doesn't throw and exception. Image does not support
> the RenderedImage interface. You need to use a BufferedImage.

It works
Thank you for your help
F