Question

I am trying to use LINQ on my ObservableCollection to group some values in each object. To keep things simple, suppose MyObject has one property:

public List<string> UserNames;

I want to write a LINQ query that returns all the strings in UserNames for each object in the collection – then group them all by the actual name. I would like the end result to show each unique name and the count of how many times that name was found in the collection.

This is easy to do with T-Sql, but I’m not having any luck with Linq to Objects.

Thanks,

Answer 1

How about this?

var allUnique = myColl.SelectMany(x => x.UserNames).GroupBy(z=>z);

foreach (var s in allUnique )
{
    Console.WriteLine(s.Key.ToString() + " Count: " + s.Count().ToString());
}