CODEWITHSUNDEEP
c#asp.netlinqlistcasting
Anyname Donotcare
Anyname Donotcare

Reputation: 11403

How to select from list filtering through IN

Q:

I have a list of objects like this:

List<object> entities = GetallEntities();

The first object in the previous list is : List<Books>.

Now i wanna to get all the books which id

exist in the following list:

List<string> BookIds = new List<string>();

Upvotes: 0

Views: 84

Answers (2)

Strillo
Strillo

Reputation: 2972

public class Book
{
    public string id { get; set; }
}

...

List<object> entities = new List<object> { new Book { id = "1" }, new Book { id = "2" } };
List<string> bookIds = new List<string> { "2" };

IEnumerable<object> books = entities.Where(e => e is Book && bookIds.Contains(((Book)e).id));

Upvotes: 2

Jan
Jan

Reputation: 16042

Assuming that your Books class has an Id property and one instance represents one book:

// Get the first element of your entity-list which is of type `List<Books>`
List<Books> bookList = entities.OfType<List<Books>>().First();
List<string> BookIds = new List<string>();
// fill your id list here ...

// filter your books by the list of ids
IEnumerable<Books> filteredBooks = 
               bookList.Where(b => BookIds.Any(id => id == b.Id);

Upvotes: 2

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