Unable to cast object of type 'WhereSelectListIterator` in LINQ

Question

I have BackgroundWorkerCollection which is a list of a specific class. When i try to loop into the list and filter and select a single i'm getting the mentioned error.

//Code

Dim bw = From BackgroundWorkerLinq In BackgroundWorkerCollection Where BackgroundWorkerLinq.Id = sItemNo Select BackgroundWorkerLinq.Backgroundworker

Is it possible to convert the bw to Backgroundworker, the class created in the application has two properties Id(int) and Backgroundworker(Backgroundworker). So i have to convert back to the same to check if that is busy or not.

Where i'm wrong and how to achieve that?

Answer 1

bw will be a sequence of BackgroundWorker items - so you can't cast from that sequence to a single item. There are a number of methods which will give you a single item, e.g.

• First
• FirstOrDefault
• Single
• SingleOrDefault
• Last
• LastOrDefault

You should work out whether you should use one of those, or actually iterate over all the results of the query.