Set Canvas Background Image to Picture

I made an app and want to add one more screen that will show route picture which all week changes with new one. So I was thinking like set Canvas.BackgroundImage to "/Route/route.png" but I don't know how to do it correctly. I will replace the picture once a week foır changing canvas image. Canvas image will be like "/Route/route.png" and I will replace new picture route.png with the same name as you see. Do you have any idea to do it?

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If gals are included:

Assuming that you do not want to distribute your app again every week, you need a place where from it would be possible to download your picture.

Look here at Taifun's example to download files: http://puravidaapps.com/filedownload.php

download.aia
downloadAuth.aia

Once you have downloaded it, you just set the images of the canvas to the downloaded file, probably it looks like set Canvas BackgroundImage to /sdcard/Route/route.png, assuming you have downloaded your image to Route/route.png

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