- Create a folder (e.g.
images
) in your Visual Studio Project. - Add the image file(s) to that folder.
- Set their
Build Action
toResource
(in the Properties window, see second image in this answer).
Then write the UriSource
property like you already did:
UriSource="/images/jamsnaps-dark.png"
That URI is effectively a Resource File Pack URI, where the prefix is automatically added by the XAML Parser.
In code behind, you would write
bitmap.UriSource = new Uri("pack://application:,,,/images/jamsnaps-dark.png");