string[] fruits = { "grape", "passionfruit", "banana", "apple", 
                      "orange", "raspberry", "mango", "blueberry" };

// Sort the strings first by their length and then 
// alphabetically by passing the identity selector function.
IEnumerable<string> query =
    fruits.AsQueryable()
    .OrderBy(fruit => fruit.Length).ThenBy(fruit => fruit);

foreach (string fruit in query)
    Console.WriteLine(fruit);

//引入命名空间
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
    public static void Main() {

        string[] presidents = {"ant", "arding", "arrison", "eyes", "over", "Jackson"};

        IEnumerable<string> items = presidents.OrderBy(s => s.Length).ThenBy(s => s);

        foreach (string item in items)
            Console.WriteLine(item);
    }
}