Why am I getting an IOException when I try to use an image file that was added to the project as a reference?

I have one IValueConverter

in WPF that converts a relative file path.

Code:

public class RelativeImagePathToImage : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var relativePath = (string)value;
        if (string.IsNullOrEmpty(relativePath)) return Binding.DoNothing;
        var path = "pack://application:,,,/" + value;
        var uri = new Uri(path);
        return new BitmapImage(uri);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return Binding.DoNothing;
    }
}

      

        
        
        
      

    

Problem:

This converter worked fine until I tried to use it with a file that was added to the project as a link (Solution Explorer -> Add existing item -> Add as a link). The image file is BuildAction

set to Content

, and the file is checked Copy Always

. The file is definitely copied to the "bin" folder correctly, but for some reason the converter chokes when it comes to return new BitmapImage(uri)

.

An exception:

System.IO.IOException was unhandled
Message="Cannot locate resource 'images/splash.png'."
Source="PresentationFramework"

      

        
        
        
      

    

Questions:

Can someone explain this? Is this a bug in the .NET Framework or is this expected behavior? Is there a workaround or "Add as link" rather than an option for image files?

Edit:

Ok I found a workaround. Here's my revised converter class:

public class RelativeImagePathToImage : IValueConverter
{
    private static string _rootPath = Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var relativePath = (string)value;
        if (string.IsNullOrEmpty(relativePath)) return Binding.DoNothing;
        var path = _rootPath + "/" + relativePath;
        var uri = new Uri(path);
        return new BitmapImage(uri);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return Binding.DoNothing;
    }
}

      

        
        
        
      

    

Apparently there is some kind of usage issue packuri

with the linked file. But why?