How to filter or query an object collecting based upon an array in C# Linq

Question

I have a C# collection of custom objects, say BookUsers, which has UserID as one of the property. I have a string array of UserID's in a separate variable. I want to get the subset of the BookUsers collection filtered by the UserID's in the string array. Please let me know how to do this using Linq.

Thanks

Answer 1

bookusers.Where(b=>ids.Contains(b.UserId))

您可能需要考虑将用户ID数组放入HashSet中，以减少内部查询的复杂性。