How can I set LINQ SelectMany projection via Func parameter?

Question

I have a function which returns a list of property values from a collection:

 public static List<string> GetSpeakerList()
 {
  var Videos = QueryVideos(HttpContext.Current);
  return Videos.Where(v => v.Type == "exampleType"
   .SelectMany(v => v.SpeakerName)
   .Distinct()
   .OrderBy(s => s)
   .ToList();
 }

I'd like to have a generic version which will let me determine which field I'd like projected - say instead of SpeakerName I'd like to allow selecting Video.Length or Video.Type.

I understand that SelectMany takes a Func, so what's the best way to make the Func configurable to allow passing it as a parameter into this function?

Answer 1

Add the function as a parameter to the method.

public static List<string> GetVideosAttribute( Func<Video,string> selector )
{
    var Videos = QueryVideos(HttpContext.Current);
    return Videos.Where(v => v.Type == "exampleType"
                 .Select( selector )
                 .Distinct()
                 .OrderBy(s => s)
                 .ToList();
}


var speakers = GetVideosAttribute( v => v->SpeakerName );
var topics = GetVideosAttribute( v => v->Topic );

Answer 2

Do you really need SelectMany?

From what I read of MSDN, it is used to flatten sequences into a sequence, which I cannot understand from your example.

I guess you need a Select instead.
Correct me, if I am wrong.