How to select values and key in a Dictionary of lists?

Question

I have this data :

public class MetaLink
{
 public long LinkNumbering { get; set; }
 public long TargetPageId { get; set; }
 public string TargetUrl { get; set; }
 public LinkType LinkOfType { get; set; }
}
public static ConcurrentDictionary<int, List<MetaLink>> Links = new ConcurrentDictionary<int, List<MetaLink>>();

How can I obtain all index of MetaLink object in the list dictionnary values and the correspondig dictionnary key with TargetUrl property == "Some value"

Perhaps is possible with Linq, but I don't find it. I do this :

var someLinks = Links.Values.Where(kvp => kvp.Any(ml => ml.TargetUrl == "Some value"));

But I can't get the correspondig dictionnary int key

• Jon Skeet: Your run-on sentence is really hard to parse. It would be much easier to help if you if you'd give a concrete example with sample input and expected output - ideally with what you've tried so far, too.

Answer 1

You're close - you want

var someLinks = Links.Where(kvp => kvp.Value.Any(ml => ml.TargetUrl == "Some value")) 
 // all key.value pairs where the Value contains the target URL
 .Select(kvp => kvp.Key); //keys for those values

Answer 2

Give a try on this. Haven't compiled.

var key = Links.Where(kvp => kvp.Value.Any(ml => ml.TargetUrl == "Some value")).Select(x => x.Key).SingleOrDefault();