several TImages, 1 hPalette -> problem

I use several TImages to display data. They all need the same colours, so I made 1 logical palette and 1 hPalette, which I assigned to the Picture.Bitmap.Palette property of all TImages. I use CopyRect to copy part of a memory bitmap to the TImages. This goes OK, unless I mirror the data in the CopyRect. (by passing for the source rect: Bounds(width-1, 0, -width, height-1)). Then the TImage stays black. If I give every TImage its own hPalette, the mirroring goes fine.

My questions:
1- is what I try at all posiible, or do all TImages always need  a unique hPalette?
2- if it is possible, what should I change to make it work?

thanks,

Wim
cadenzaAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

cadenzaAuthor Commented:
Edited text of question
0
jorgen.hojdmoCommented:
Hi!

I have had the same problem, but could not make it work properly by assigning the palette property. A workaround is to use the WinAPI. Before you draw on the bitmap call:

SelectPalette(Bitmap.Canvas.Handle,YourHPalette,false);
RealizePalette(Bitmap.Canvas.Handle);

This will work fine if you do not assign the Palette.

Call the select and realize everytime your app gets focus.


0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
mirek071497Commented:
This is fine however better way is to remember the hPalette in your program and use SelectPalette( savedpalette .....
at the end of pgm you must delete this object.

BTW SelectPalette  returns previous palette so you must save this and then restore. You can loose resources if this will not be done !.

prevpal := SelectPalette( ...
...
any code
...
SlelectPalette( prevpal

this is good idea to save resources without loose.

sorry for my english.
0
cadenzaAuthor Commented:
Thanks for the answer and valuable comment. This not only will save me time, but, as I understand from Mirek's comment, resources as well !!!

Wim
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Delphi

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.