LISTVIEW_SetItemBitmap

crivelma · Oct 17th 2019, 5:30pm

Hi all.
I have an issue regarding the creation of a page with emWin that is using LISTVIEW_SetItemBitmap.

I want to put all bitmap on flash filesystem and load them one by one with LISTVIEW_SetItemBitma.

The fact is that the function require a (const GUI_BITMAP *) so I create a SRAM buffer with this structure that I use as temporary storage.

So the code looks like:
guiGenData = GUIResourceLoadBitmap( image1 ) ;

LISTVIEW_SetItemBitmap( hListId, 0, row, 0, 0, (const GUI_BITMAP *)&guiGenData );

guiGenData = GUIResourceLoadBitmap( image2 ) ;

LISTVIEW_SetItemBitmap( hListId, 0, row, 0, 0, (const GUI_BITMAP *)&guiGenData );

guiGenData = GUIResourceLoadBitmap( image3 ) ;

LISTVIEW_SetItemBitmap( hListId, 0, row, 0, 0, (const GUI_BITMAP *)&guiGenData );

When the page is create I see that all images are equal to image3. What's the matter?

Thanks in advance,
Marco Crivellari

SEGGER - Florian · Oct 24th 2019, 4:58pm

Hi Marco,

all bitmap pointers you set must be valid the whole time you use them. Since you use the same pointer every time, all item bitmaps now point to the same address (which is the one from when you last loaded the bitmap).
To solve this, simply use different pointer variables for each different bitmap.

After you don't need the bitmaps anymore, e.g. after you deleted the window, the pointers don't have to be valid anymore.

Best regards,

Florian

LISTVIEW_SetItemBitmap

LISTVIEW_SetItemBitmap

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