Answer by Spongman for How to get relative path from absolute path

here's mine:

public static string RelativePathTo(this System.IO.DirectoryInfo @this, string to){    var rgFrom = @this.FullName.Split(new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }, StringSplitOptions.RemoveEmptyEntries);    var rgTo = to.Split(new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }, StringSplitOptions.RemoveEmptyEntries);    var cSame = rgFrom.TakeWhile((p, i) => i < rgTo.Length && string.Equals(p, rgTo[i])).Count();    return Path.Combine(        Enumerable.Range(0, rgFrom.Length - cSame)        .Select(_ => "..")        .Concat(rgTo.Skip(cSame))        .ToArray()    );}