Imagelist Destroys Background Transparency of Images!!!

[James Graham]

I've got a problem with using images with transparent backgrounds.

If I convert a bmp image to a png image (via a graphics editor...in this
case Microsoft Photo Editor) and then place the png into a picturebox, the
background is transparent and has the same color as the form background that
the picture is place upon.

Here's the problem.....

If I have a number of png images loaded into an imagelist, and I retrieve
one of those images into a picturebox rather than directly from a file, the
background transparency seems to go away, and the background of the image
is solid white.

To Summarize:
Saving an image with a transparent background as a .png format image file,
then placing that file into a picturebox works (background is transparent).

But putting that same .png image into an imagelist, then retreiving the image
from the imagelist into a picturebox "breaks" the transparency.

Is there a workaround for this or am I going to have to throw away the imagelist
and opt for a resource file? Even worse, am I going to have to retreive
the image from a disk file? I hope not. I've got 45 images to deal with!

Thanks,
Jim Graham
--
graham@iucf.indiana.edu

[Constance J. Petersen]

Hi Jim,

"James Graham" <graham@iucf.indiana.edu> wrote in message
news:3c940f95$1@10.1.10.29...
> If I have a number of png images loaded into an imagelist, and I retrieve
> one of those images into a picturebox rather than directly from a file, the
> background transparency seems to go away, and the background of the image
> is solid white.

I think your problem might be with the png created by Microsoft Photo Editor.

I've tested this with a transparent png that I made with Macromedia Fireworks
3.0, and transparency is preserved.
--
Constance Petersen, DevX newsgroup section leader
SoftMedia Artisans, Inc.
http://www.smartisans.com
For useful, usable software and Web sites
Featured Web design: http://www.keweenawnow.com/
--
Please reply in the newsgroup so everyone can benefit

[James Graham]

Constance, thanks for your reply.

I just discovered that it's not technically a problem, but I still can't
explain why it's happening.

As it turns out, the .png images in my imagelist are intact after all.

What I had not checked when I composed my posting to this list was the BackColor
of the control form. If I set my control's form backcolor to that of the
parent application form's backcolor, all is well.

The difference, which I can't explain, is that the background color of the
image in my control during design-time OF THE CONTROL, is AUTOMATICALLY transparent
to the usercontrol's form. Changing the usercontrol's form also appears
"through" the background of the image I retreived from my imagelist.

But....I have to deliberately SET the backcolor of my usercontrol when it's
placed on another form. I can live with that, and I suspect it's perfectly
normal....I just can't explain it .

Thanks again,
Jim Graham
--
graham@iucf.indiana.edu




"Constance J. Petersen" <constance@smartisans.com> wrote:
>Hi Jim,
>
>"James Graham" <graham@iucf.indiana.edu> wrote in message
>news:3c940f95$1@10.1.10.29...
>> If I have a number of png images loaded into an imagelist, and I retrieve
>> one of those images into a picturebox rather than directly from a file,
the
>> background transparency seems to go away, and the background of the image
>> is solid white.
>
>I think your problem might be with the png created by Microsoft Photo Editor.
>
>I've tested this with a transparent png that I made with Macromedia Fireworks
>3.0, and transparency is preserved.
>--
>Constance Petersen, DevX newsgroup section leader
>SoftMedia Artisans, Inc.
>http://www.smartisans.com
>For useful, usable software and Web sites
>Featured Web design: http://www.keweenawnow.com/
>--
>Please reply in the newsgroup so everyone can benefit
>
>
>