IMGButton bug?

[Peter Redei]

It seems to me the GDI memory fairly fast evaporates when changing the images in image buttons.
Here is a little test program:
#COMPILE EXE
#INCLUDE "WIN32API.INC"
#RESOURCE "Test.PBR"

GLOBAL hDlg AS LONG
GLOBAL tTimer AS LONG
GLOBAL counter AS LONG
$Image1 = "EmptyWhite"
$Image2 = "EmptyBlack"
DECLARE CALLBACK FUNCTION DlgProc
FUNCTION PBMAIN () AS LONG
#REGISTER NONE

DIALOG NEW %NULL, "Test", ,, 340, 230, %WS_MINIMIZEBOX OR %DS_3DLOOK OR %DS_CENTER OR %DS_MODALFRAME OR %WS_SYSMENU, 0 TO hDlg

CONTROL ADD IMGBUTTON, hDlg, 1001, $Image1, 0, 0, 30, 28, %BS_FLAT
CONTROL ADD IMGBUTTON, hDlg, 1002, $Image2, 30, 0, 30, 28, %BS_FLAT
CONTROL ADD LABEL, hDlg, 1003, "Counter: 0", 250, 65, 48, 14

DIALOG SHOW MODAL hDlg CALL DlgProc
END FUNCTION

CALLBACK FUNCTION DlgProc
SELECT CASE CBMSG
CASE %WM_INITDIALOG
tTimer = SetTimer(0, 0, 100, CODEPTR( ThinkingProc ))
CASE %WM_DESTROY
IF tTimer > 0 THEN
KillTimer 0, tTimer
END IF
END SELECT
END FUNCTION
SUB ThinkingProc(BYVAL hWnd AS LONG, BYVAL uMsg AS LONG, BYVAL idEvent AS LONG, BYVAL lngSysTime AS LONG)
DIM txt AS STRING
'switch images
INCR counter
IF counter MOD 2 = 0 THEN
CONTROL SET IMGBUTTON hDlg, 1001, $Image2
CONTROL SET IMGBUTTON hDlg, 1002, $Image1
ELSE
CONTROL SET IMGBUTTON hDlg, 1001, $Image1
CONTROL SET IMGBUTTON hDlg, 1002, $Image2
END IF
txt = "Counter: " & FORMAT$(counter)
CONTROL SET TEXT hDlg, 1003, txt
END SUB

The Test.rc file looks like:
#INCLUDE "resource.h"
EmptyBlack BITMAP C:\Bmp\EmptyBlack.bmp
EmptyWhite BITMAP C:\Bmp\EmptyWhite.bmp

where the two images are two squares with the size of the button, in different colors.

On my machine using Windows'98 about at 340 counter value the program consumes all the GDI memory (the colors will no longer change).

Unloading the program from memory releases the memory.
What is the workaround?


Sincerely,


Peter Redei


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[Chris Boss]

Peter;

If I remember correctly, the DDT Image commands "load" a Bitmap
each time you use them and you are not simply toggling between
Bitmaps, but loading a new instance of the Bitmap everytime.

If your toggling of the images continue, you are loading hundreds
of instances of the bitmaps (big GDI drain).

What you need to do, is either destroy (deleteobject) the previous bitmap
after the new one is loaded or load the bitmaps one time and then
use SendMessage to send the control the new Bitmap Handle.

DDT is loading the Bitmap again and again. Bitmaps should be
loaded once and then only the "handle" being passed to the
control, which DDT does not do.

You simply must resort to the API to attach the Bitmap to a control.



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[Lance Edmonds]

this has been covered a few times here before... take a look at http://www.powerbasic.com/support/pb...ead.php?t=1826


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lance
powerbasic support
mailto:[email protected][email protected]</a>

[Peter Redei]

Thank you Lance and Chris.
Lance, your "trick" seems to work fine with an Image control.
It also worked with the the IMGBUTTON control using %BM_GETIMAGE instead of %STM_GETIMAGE..

Using Chris advise the CONTROL SEND hDlg, 1001, %BM_SETIMAGE, %IMAGE_BITMAP, hBmp
also a good solution.

Thank you for both.

Sincerely,


Peter Redei



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