Memory leak with GUICtrlSendMsg and Picture control

[lIlIIlIllIIIIlI]

$img = GUICtrlCreatePic("", 500,0,1390,890)

    ...

    _GDIPlus_Startup()
    local $bitmap_1 = _GDIPlus_BitmapCreateFromMemory(InetRead($jpg_url))
    local $bitmap_2 = _GDIPlus_ImageResize ($bitmap_1, 1390, 890)
    local $bitmap_3 = _GDIPlus_BitmapCreateHBITMAPFromBitmap($bitmap_2)
    GUICtrlSendMsg($img, 0x0172, 0, $bitmap_3)

    _GDIPlus_BitmapDispose($bitmap_1)
    _GDIPlus_BitmapDispose($bitmap_2)
    _WinAPI_DeleteObject($bitmap_3)
    _GDIPlus_Shutdown()

I think this is all the relevant code. I've never worked with any of these functions before (aside from GUICtrlCreatePic and setting it to a picture file, not setting it via memory via GUICtrlSendMsg) so I don't know how to clean up properly after loading/drawing an image to screen. I commented out everything and went line by line figuring out what stops the leak. BitmapDispose and DeleteObject work for the varables I created... $bitmap_1, 2, 3 are good. Now all that remains is the  GUICtrlSendMsg line of code. When I comment just this line, the memory leak stops. Do I need to do something to clear the picture control? Or send a message to $img using GUICtrlSendMsg telling it to clear the previous image? The docs for the function don't show anything (https://www.autoitscript.com/autoit3/docs/functions/GUICtrlSendMsg.htm) but I see it's being used to start/stop a marquee scrolling text for a progress bar control with the third parameter value 0/1... I tried this with Pic control thinking making 0 is for displaying the bitmap, and 1 is for clearing it, but it doesn't clear the memory.

Help would be appreciated, thanks.

Edited April 5, 2024 by lIlIIlIllIIIIlI
more info

[Andreik]

You need to delete the object returned by GUICtrlSendMsg().

_WinAPI_DeleteObject(GUICtrlSendMsg($img, 0x0172, 0, $bitmap_3))

 

Quote

Do I need to do something to clear the picture control? Or send a message to $img using GUICtrlSendMsg telling it to clear the previous image? The docs for the function don't show anything (https://www.autoitscript.com/autoit3/docs/functions/GUICtrlSendMsg.htm) but I see it's being used to start/stop a marquee scrolling text for a progress bar control with the third parameter value 0/1... I tried this with Pic control thinking making 0 is for displaying the bitmap, and 1 is for clearing it, but it doesn't clear the memory.

The message you send to the control is STM_SETIMAGE and doesn't star/stop anything but set a new image. The third parameter is IMAGE_BITMAP and specifies the type of image to associate with the control. Also the return value is a handle to the image previously associated with the control (or NULL) so it must be deleted properly.

Edited April 5, 2024 by Andreik

[lIlIIlIllIIIIlI]

7 hours ago, Andreik said:

You need to delete the object returned by GUICtrlSendMsg().

_WinAPI_DeleteObject(GUICtrlSendMsg($img, 0x0172, 0, $bitmap_3))

 

The message you send to the control is STM_SETIMAGE and doesn't star/stop anything but set a new image. The third parameter is IMAGE_BITMAP and specifies the type of image to associate with the control. Also the return value is a handle to the image previously associated with the control (or NULL) so it must be deleted properly.

Ah, the function returns something! That makes so much sense, thanks.