Let’s say you have a Dictionary called fooDictionary
fooDictionary.Values.ToList().IndexOf(someValue);
Values.ToList()
converts your dictionary values into a List of someValue objects.
IndexOf(someValue)
searches your new List looking for the someValue object in question
and returns the Index which would match the index of the Key/Value pair in the dictionary.
This method does not care about the dictionary keys, it simply returns the index of the value that you are looking for.
This does not however account for the issue that there may be several matching “someValue” objects.