Question

I have a collection List<CustomClass> which I am trying to find a way to return a field which corresponds to another field that occurs the highest number of times.
I’ve asked a similar question in the past, but I’m not sure how to extend the logic to a custom class.
For instance.

My CustomClass has three public properties:

Title
Mid
Eid

And a List<CustomClass> MatchedFeatures = List<CustomClass>(); is populated in a loop.

I need to perform a Linq operation to return the Mid of the class that has the largest number of occurring identical Eid‘s. So we are counting the identical Eid columns.

I have tried using

var TopResult = MatchedFeatures.GroupBy(MatchedFeature => MatchedFeature).OrderByDescending(group => group.Count()).FirstOrDefault();

But it doesn’t return what I am looking for.

Can anyone see where I am going wrong? I am using C#

Here is the previous asked question, which seems to work fine. Now how to extend it in this case…?
Simple LINQ question in C#

Many thanks,
Brett

Answer 1

If you want to group those features where the Eid property is the same, you should use GroupBy(MatchedFeature => MatchedFeature.Eid).

If you leave out the .Eid it will only group those features together which are entirely the same – not the ones that have the same Eid.