Resource URI in WPF UserControl, which is hosted in Windows Forms application

Question

I have a WPF UserControl, which is using some PNG bitmap resources as part of it's UI. Currently, those files are referenced with Build Action: Content and a Copy to Output Directory: Do not copy. Elements on this UserControl are using following URI to access the resource: pack://application:,,,Resources/ui/Cross.png which works fine in designer.

The user control is then used in a Windows Forms application through ElementHost control at which point all image links stop working. The UserControl is in it's own assembly and Windows Forms application is referencing that assembly.

I have also tried changing the URI to this: pack://application:,,,Assembly.Name;component/Resources/ui/Cross.png

I have further tried reading this to no help.

The only option I have left is to include code to manually set ImageSource of all Image elements on the user control, which would require a lot of work. I feel like there must be a way to resolve this better.

Answer 1

Build Action: Content and a Copy to Output Directory: Do not copy

That combination does not work. Content requires that the file is copied.

However, you should use Build Action Resource. And your Pack URI misses a slash after ,,,.

It should be

pack://application:,,,/AssemblyName;component/Resources/ui/Cross.png

provided that the image file is part of your Visual Studio Project, located in a subfolder named ui in a project folder named Resources.

See Resource File Pack URIs for details.