Jak mogę uzyskać dostęp do indeksu pętli wewnątrz wybierz LINQ?

Question

ten kod:

var customers = from cust in Customers 
    group cust by new {cust.Country} into grouping 
    select new 
    { 
     Country = grouping.Key.Country, 
     Customers = grouping 
    }; 

customers.ToList().ForEach(g => 
    Console.WriteLine("{0} has {1} customers: {2}", 
     g.Country, 
     g.Customers.Count(), 
     String.Join(", ",g.Customers.Select(x => "#. " + x.CompanyName).ToArray()) 
    )); 

customers.Dump(); 

daje wyniki:

Argentina has 3 customers: #. Cactus Comidas para llevar, #. Océano Atlántico Ltda., #. Rancho grande 
Austria has 2 customers: #. Ernst Handel, #. Piccolo und mehr 
Belgium has 2 customers: #. Maison Dewey, #. Suprêmes délices 
Brazil has 9 customers: #. Comércio Mineiro, #. Familia Arquibaldo, #. Gourmet Lanchonetes, #. Hanari Carnes, #. Que Delícia, #. Queen Cozinha, #. Ricardo Adocicados, #. Tradição Hipermercados, #. Wellington Importadora 
Canada has 3 customers: #. Bottom-Dollar Markets, #. Laughing Bacchus Wine Cellars, #. Mère Paillarde 
Denmark has 2 customers: #. Simons bistro, #. Vaffeljernet 
... 

Jak mogę wymienić "#" z indeksem/liczby, tak aby uzyskać wyniki takie jak:

Argentina has 3 customers: 1. Cactus Comidas para llevar, 2. Océano Atlántico Ltda., 3. Rancho grande 
... 

Answer 1

customers.ToList().ForEach(g => Console.WriteLine("{0} has {1} customers: {2}", 
    g.Country, 
    g.Customers.Count(), 
    string.Join(", ", 
     g.Customers.Select((x, i) => i + ". " + x.CompanyName).ToArray()))); 

Answer 2

Spróbuj utworzyć int x = 0; przed twoim zdaniem linq. Następnie wewnątrz, wydrukuj (x ++). ToString().

Spowoduje to zamknięcie x.

Answer 3

można to zrobić w celu poszukiwania wartości indeksu iteratora:

var customers = from cust in Customers 
//Get Current Index 
let currIndex = Customers.IndexOf(cust) 
//You can then make use of the index in the Variable currIndex