Control.picture and Bitblt'ing

[ConvertFromOldNGs]

by Jens Richnow >> Fri, 2 Feb 2001 0:40:23 GMT

Could somebody please help with some basic API stuff linked to JADE (since I'm not too familar with the in's and out's of the Windows API).

Basically what I want to achieve is taking a number of images, stored as Binaries in a Class, manipulate these images using API's (Bitblt, StretchBlt, etc.) and MemoryDC's, and finally pass the finished image back into the Control.picture property for temporary storage/display.

If I leave the Jade part out of the equation, everything works fine: I can read the images from a file, manipulate the images using MemoryDC's and display (bitblt) the finished image on the appropriate control. Now I don't wont to do this stuff all the time when the Control needs to be repainted (form minimised; form partially or completely covered by another form; different button states, etc.). Can the image created (using, for instance, CreateCompatibleBitmap) be stored as a binary in the Control.picture property (or Class.image [Binary], for that matter)? All, I've got at the moment is the handle to the DC, but nothing to the bitmap itself.

Any help is greatly appreciated.

Jens

[ConvertFromOldNGs]

by David Mitchell >> Fri, 2 Feb 2001 1:21:15 GMT

Once you have BitBlt'ed onto the control you should be able to use createPicture, which returns a binary.

David

[ConvertFromOldNGs]

by Jens Richnow >> Fri, 2 Feb 2001 2:22:47 GMT

I just tried it, but the image stored is that of the control itself rather then the bitblt'ed image "draped" over the control:

vars pic :Binary;begin

... all the bitblt'ing resulting in dislaying the finished image on the button...
pic := button3.createPicture(true, false, 24);
pic.convertToFile("C:\Temp\Test.png", PictureType_Png);
button3.picture := pic;
end;

I added teh picture file save to confirm which image is actually created, and it alsways that of the Windows-like button3 control itself.

Do I miss something, or is there a timing issue involved?

Regards

Jens

[ConvertFromOldNGs]

by Carl Ranson >> Sun, 4 Feb 2001 20:51:38 GMT

I've done some stuff like this before, you're best bet is to take control of the painting yourself and do it with the win API's.

Cheers,
CR