Sure, I've a button group that holds multiple buttons with different ids, and they all have a placeholder iconUri and focusedIconUri, my intention is to change these icons with a network Image that I receive from the API(that image is not always 64px)
<ButtonGroup>
....
<Button id="id1" minWidth="64" maxWidth="64"
height="64" text=""
focusBitmapUri="pkg:/images/transparent.9.png"
focusFootprintBitmapUri="pkg:/images/transparent.9.png"
iconUri="pkg:/images/2_quality.png"
focusedIconUri="pkg:/images/2_quality.png" />
...
</ButtonGroup>
On the brightscript side of the code, I've a task that loads info from api and then I just try to set the field
m.btn1.iconUri = m.top.response.apiImage
m.btn1.focusedIconUri = m.top.response.apiImage
Let me know if you need any other information.