如何：使用自动实现的属性实现轻量类

// This class is immutable. After an object is created, 
    // it cannot be modified from outside the class. It uses a 
    // constructor to initialize its properties. 
    class Contact
    {
        // Read-only properties. 
        public string Name { get; }
        public string Address { get; private set; }

        // Public constructor. 
        public Contact(string contactName, string contactAddress)
        {
            Name = contactName;
            Address = contactAddress;               
        }
    }

    // This class is immutable. After an object is created, 
    // it cannot be modified from outside the class. It uses a 
    // static method and private constructor to initialize its properties.    
    public class Contact2
    {
        // Read-only properties. 
        public string Name { get; private set; }
        public string Address { get; }

        // Private constructor. 
        private Contact2(string contactName, string contactAddress)
        {
            Name = contactName;
            Address = contactAddress;               
        }

        // Public factory method. 
        public static Contact2 CreateContact(string name, string address)
        {
            return new Contact2(name, address);
        }
    }

    public class Program
    { 
        static void Main()
        {
            // Some simple data sources. 
            string[] names = {"Terry Adams","Fadi Fakhouri", "Hanying Feng", 
                              "Cesar Garcia", "Debra Garcia"};
            string[] addresses = {"123 Main St.", "345 Cypress Ave.", "678 1st Ave",
                                  "12 108th St.", "89 E. 42nd St."};

            // Simple query to demonstrate object creation in select clause. 
            // Create Contact objects by using a constructor. 
            var query1 = from i in Enumerable.Range(0, 5)
                        select new Contact(names[i], addresses[i]);

            // List elements cannot be modified by client code. 
            var list = query1.ToList();
            foreach (var contact in list)
            {
                Console.WriteLine("{0}, {1}", contact.Name, contact.Address);
            }

            // Create Contact2 objects by using a static factory method. 
            var query2 = from i in Enumerable.Range(0, 5)
                         select Contact2.CreateContact(names[i], addresses[i]);

            // Console output is identical to query1. 
            var list2 = query2.ToList();

            // List elements cannot be modified by client code. 
            // CS0272: 
            // list2[0].Name = "Eugene Zabokritski"; 

            // Keep the console open in debug mode.
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();                
        }
    }

/* Output:
    Terry Adams, 123 Main St.
    Fadi Fakhouri, 345 Cypress Ave.
    Hanying Feng, 678 1st Ave
    Cesar Garcia, 12 108th St.
    Debra Garcia, 89 E. 42nd St.
*/