问题
I am new to Linq. I have a Customers table.ID,FullName,Organization,Location being the columns. I have a query in Sqlite returning me 2500 records of customers. I have to find the index of the customer where ID=150 for example from this result set. Its a List of Customers. The result set of the query is ordered by organization. I tried with FindIndex and IndexOf but getting errors for the former and -1 for the latter. So, how should it be done? Thanks.
回答1:
You don't need to use LINQ, you can use FindIndex of List<T>:
int index = customers.FindIndex(c => c.ID == 150);
回答2:
Linq to Objects has overloaded Select method
customers.Select((c,i) => new { Customer = c, Index = i })
.Where(x => x.Customer.ID == 150)
.Select(x => x.Index);
Keep in mind, that you should have in-memory List<Customer> to use this Linq to Objects method.
来源：https://stackoverflow.com/questions/18108778/get-index-of-object-in-a-list-using-linq