Question

I’m trying to make a group by statement using LINQ. I am getting an error The name ‘con’ does not exist in the current context.

In my code after the select, I trying to get the ActivityID value but the list ‘con’ unavailable.

List<Contribution> contributions =
    contLogic.GetAllContibutionsByActivityIDToList(ActivityID);

var groups = from con in contributions
             group con by con.Response
             into gResponse
             select new
             {
                grop = gResponse.Count(),
                con.ActivityID
             };

I have look at Microsoft samples, and I don’t know what I did wrong.

Microsoft sample:

List<Product> products = GetProductList();

var orderGroups = from prod in products
                  group prod by prod.Category into prodGroup
                  select new { Category = prodGroup.Key, Products = prodGroup };

ObjectDumper.Write(orderGroups, 1);

Answer 1

con isn’t in scope in your grouping. Note that in the Microsoft example, their original query element was prod, but after the grouping, they referred to prodGroup.

Your query is grouping the elements together based upon a common Response, you are essentially “losing” the individual con for the greater whole. You may need to expand your grouping to include more criteria than just the Response, such as

group by new { con.Response, con.ActivityID }

and then refer to the ID via

gResponse.Key.ActivityID

Or perhaps access perhaps the first element’s ActivityID inside each group

gResponse.First().ActivityID

Without more information as to what you are trying to accomplish, I cannot give specific advice for how you need to proceed.