A Simple Solution to Some Problems with Asynchrony in Silverlight

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.Threading;
using TaskManagerDemo.Web.DataContracts;

namespace TaskManagerDemo.Web
{
    // NOTE: If you change the class name "ExampleService" here, you must also update the reference to "ExampleService" in Web.config.
    public class ExampleService : IExampleService
    {
        public List<CityZipCode> GetSelectedCities(int factor)
        {
            // Sleep to simulate a database query that takes some time.
            Thread.Sleep(500);
            return GetRandomSelection(factor);
        }

        public List<CityZipCode> GetSelectedZipCodes(int factor)
        {
            Thread.Sleep(500);
            return GetRandomSelection(factor);
        }

        private List<CityZipCode> GetRandomSelection(int factor)
        {
            List<CityZipCode> result = GetAllCityZipCodes();
            Random random = new Random();
            int maxValue = (factor % 7) + 3;
            result = result.Where(czc => random.Next(0, maxValue) == 0).ToList();
            return result;
        }

        public List<CityZipCode> GetAllCityZipCodes()
        {
            Thread.Sleep(500);
            return new List<CityZipCode>
            {
                new CityZipCode { City = "Saginaw", ZipCode = "98541" },
                new CityZipCode { City = "Saint John", ZipCode = "99127" },
                new CityZipCode { City = "Saint John", ZipCode = "99171" },
                new CityZipCode { City = "Saint Urbans", ZipCode = "98596" },
                new CityZipCode { City = "Salkum", ZipCode = "98582" },
                new CityZipCode { City = "Samish Island", ZipCode = "98232" },
                new CityZipCode { City = "Sammamish", ZipCode = "98074" },
                new CityZipCode { City = "Sammamish", ZipCode = "98075" },
                new CityZipCode { City = "San Juan Island", ZipCode = "98250" },
                new CityZipCode { City = "Sandy Hook Park", ZipCode = "98370" },
                new CityZipCode { City = "Sappho", ZipCode = "98305" },
                new CityZipCode { City = "Satsop", ZipCode = "98951" },
                new CityZipCode { City = "Sawyer", ZipCode = "98951" },
                new CityZipCode { City = "Saxon", ZipCode = "98220" },
                new CityZipCode { City = "Scandia", ZipCode = "98370" },
                new CityZipCode { City = "Scenic", ZipCode = "98288" },
                new CityZipCode { City = "Schneiders Prairie", ZipCode = "98501" },
                new CityZipCode { City = "Seabeck", ZipCode = "98380" },
                new CityZipCode { City = "Seahurst", ZipCode = "98062" },
                new CityZipCode { City = "Seatac", ZipCode = "98148" },
                new CityZipCode { City = "Seatac", ZipCode = "98158" },
                new CityZipCode { City = "Seatac", ZipCode = "98168" },
                new CityZipCode { City = "Seatac", ZipCode = "98188" },
                new CityZipCode { City = "Seatac", ZipCode = "98198" },
                new CityZipCode { City = "Seattle", ZipCode = "98101" },
                new CityZipCode { City = "Seattle", ZipCode = "98102" },
                new CityZipCode { City = "Seattle", ZipCode = "98103" },
                new CityZipCode { City = "Seattle", ZipCode = "98104" },
            };
        }
    }
}