try
            {
                using (WebSession mywebsession = WebCore.CreateWebSession(
new WebPreferences() { CustomCSS = "::-webkit-scrollbar { visibility: hidden; }" }))
                {
                    using (var view = WebCore.CreateWebView(1240, 1000, mywebsession))
                    {
                        view.Source = new Uri("https://site.com/");

                        bool finishedLoading = false;
                        view.LoadingFrameComplete += (s, e) =>
                        {
                            if (e.IsMainFrame)
                                finishedLoading = true;
                        };

                        while (!finishedLoading)
                        {
                            Thread.Sleep(100);
                            WebCore.Update();
                        }

                        using (var surface = (BitmapSurface)view.Surface)
                        {
                            surface.SaveToJPEG("result.jpg");
                        }
                    }
                }
            }
            finally
            {
                WebCore.Shutdown();
            }

 System.InvalidOperationException: You are attempting to re-initialize the WebCore.
The WebCore must only be initialized once per process and must be shut down only when the process exits.

 System.AccessViolationException: Attempted to read or write protected memory.
This is often an indication that other memory is corrupt. at Awesomium.Core.NativeMethods.WebCore_CreateWebView_1(HandleRef jarg1, Int32 jarg2, Int32 jarg3, HandleRef jarg4)

using System;
using System.Collections.Concurrent;
using System.IO;
using System.Threading;
using System.Web;
using Awesomium.Core;

namespace AwesomiumWebModule
{
    public class AwesomiumModule : IHttpModule
    {
        private static readonly Thread WorkerThread = new Thread(awesomiumWorker);
        private static readonly ConcurrentQueue<AwesomiumRequest> TaskQueue = new ConcurrentQueue<AwesomiumRequest>();
        private static bool _isRunning = true;

        static AwesomiumModule()
        {
            WorkerThread.Start();
        }       

        private static void awesomiumWorker()
        {
            while (_isRunning)
            {
                if (TaskQueue.Count != 0)
                {
                    AwesomiumRequest outRequest;
                    if (TaskQueue.TryDequeue(out outRequest))
                    {
                        var img = AwesomiumThumbnail.FetchWebPageThumbnail(outRequest);
                        File.WriteAllBytes(outRequest.SavePath, img);
                        Thread.Sleep(500);
                    }
                }
                Thread.Sleep(5);
            }
        }

        public void Dispose()
        {
            _isRunning = false;
            WebCore.Shutdown();
        }

        public void Init(HttpApplication context)
        {
            context.EndRequest += endRequest;
        }

        static void endRequest(object sender, EventArgs e)
        {
            var url = HttpContext.Current.Items[Constants.AwesomiumRequest] as AwesomiumRequest;
            if (url!=null)
            {
                TaskQueue.Enqueue(url);
            }
        }
    }
}

<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <httpModules>
      <add name="AwesomiumWebModule" type="AwesomiumWebModule.AwesomiumModule"/>
    </httpModules>
  </system.web>

  <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
      <add name="AwesomiumWebModule" type="AwesomiumWebModule.AwesomiumModule"/>
    </modules>
  </system.webServer>
</configuration>

        protected void btnStart_Click(object sender, EventArgs e)
        {
            var host = new Uri(txtUrl.Text).Host;
            HttpContext.Current.Items.Add(Constants.AwesomiumRequest, new AwesomiumRequest
            {
                Url = txtUrl.Text,
                SavePath = Path.Combine(HttpRuntime.AppDomainAppPath, "App_Data\\Thumbnails\\" + host + ".jpg"),
                TempDir = Path.Combine(HttpRuntime.AppDomainAppPath, "App_Data\\Temp")
            });
            lblInfo.Text = "Please wait. Your request will be served shortly.";
        }

 QueryableExtensions:
AllAsync
AnyAsync
AverageAsync
ContainsAsync
CountAsync
FirstAsync
FirstOrDefaultAsync
ForEachAsync
LoadAsync
LongCountAsync
MaxAsync
MinAsync
SingleAsync
SingleOrDefaultAsync
SumAsync
ToArrayAsync
ToDictionaryAsync
ToListAsync

DbSet:
FindAsync

DbContext:
SaveChangesAsync

Database:
ExecuteSqlCommandAsync

    public class User
    {
        public int Id { get; set; }
        public string Name { get; set; }

        public virtual ICollection<BlogPost> BlogPosts { get; set; }
    }

    public class BlogPost
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }

        [ForeignKey("UserId")]
        public virtual User User { get; set; }
        public int UserId { get; set; }
    }

    public class MyContext : DbContext
    {
        public DbSet<User> Users { get; set; }
        public DbSet<BlogPost> BlogPosts { get; set; }

        public MyContext()
            : base("Connection1")
        {
            this.Database.Log = sql => Console.Write(sql);
        }
    }

        private async Task<User> addUserAsync(CancellationToken cancellationToken = default(CancellationToken))
        {
            using (var context = new MyContext())
            {
                var user = context.Users.Add(new User
                {
                    Name = "Vahid"
                });
                context.BlogPosts.Add(new BlogPost
                {
                    Content = "Test",
                    Title = "Test",
                    User = user
                });
                await context.SaveChangesAsync(cancellationToken);
                return user;
            }
        }

 [AsyncTimeout(8000)]
public async Task<ActionResult> Index(CancellationToken cancellationToken)

 var user = await addUserAsync();
Console.WriteLine("user id: {0}", user.Id);
 

        private async Task<User> updateAsync(CancellationToken cancellationToken = default(CancellationToken))
        {
            using (var context = new MyContext())
            {
                var user1 = await context.Users.FindAsync(cancellationToken, 1);
                if (user1 != null)
                    user1.Name = "Vahid N.";

                await context.SaveChangesAsync(cancellationToken);
                return user1;
            }
        }

        private async Task<int> deleteAsync(CancellationToken cancellationToken = default(CancellationToken))
        {
            using (var context = new MyContext())
            {
                var user1 = await context.Users.FindAsync(cancellationToken, 1);
                if (user1 != null)
                    context.Users.Remove(user1);

                return await context.SaveChangesAsync(cancellationToken);
            }
        }

         public async Task<List<TEntity>> GetAllAsync()
   {
    return await Task.Run(() => _tEntities.ToList());
   }

        private async Task<List<User>> getUsersAsync(CancellationToken cancellationToken = default(CancellationToken))
        {
            using (var context = new MyContext())
            {
                return await context.Users.ToListAsync(cancellationToken);
            }
        }

 internal override async Task<long> ExecuteAsync(
//...
rowsAffected = await command.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(continueOnCapturedContext: false);
//...

    var connectionString = "........";
    var sql = @"......"";
    var users = new List<User>();
 
    using (var cnx = new SqlConnection(connectionString))
    {
      using (var cmd = new SqlCommand(sql, cnx))
      {
       await cnx.OpenAsync(); 
       using (var reader = await cmd.ExecuteReaderAsync(CommandBehavior.CloseConnection))
       {
        while (await reader.ReadAsync())
        {
          var user = new User
          {
           Id = reader.GetInt32(0), 
           Name = reader.GetString(1), 
          };
         users.Add(user);
        }
       }
      }
    }

        // multiple operations
        private static async Task loadAllAsync(CancellationToken cancellationToken = default(CancellationToken))
        {
            using (var context = new MyContext())
            {
                var task1 = context.Users.ToListAsync(cancellationToken);
                var task2 = context.BlogPosts.ToListAsync(cancellationToken);

                await Task.WhenAll(task1, task2);
                // use task1.Result
            }
        }

  An unhandled exception of type 'System.NotSupportedException' occurred in mscorlib.dll
 Additional information: A second operation started on this context before a previous asynchronous operation completed.
Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context.
Any instance members are not guaranteed to be thread safe.

namespace ExplorerPCal.Hooks
{
    public class GetDateTimeFormatInjection : IEntryPoint
    {

        public GetDateTimeFormatInjection(RemoteHooking.IContext context, string channelName)
        {
            // connect to host...
            _interface = RemoteHooking.IpcConnectClient<MessagesReceiverInterface>(channelName);
            _interface.Ping();
        }

        public void Run(RemoteHooking.IContext context, string channelName)
        {
        }
    }
}

        public void Run(RemoteHooking.IContext context, string channelName)
        {
                GetDateFormatHook = LocalHook.Create(
                                        InTargetProc: LocalHook.GetProcAddress("kernel32.dll", "GetDateFormatW"),
                                        InNewProc: new GetDateFormatDelegate(getDateFormatInterceptor),
                                        InCallback: this);

        [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Auto, SetLastError = true)]
        public static extern int GetDateFormatW(
                                        uint locale,
                                        uint dwFlags, // NLS_DATE_FLAGS
                                        SystemTime lpDate,
                                        [MarshalAs(UnmanagedType.LPWStr)] string lpFormat,
                                        StringBuilder lpDateStr,
                                        int sbSize);

        [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Auto, SetLastError = true)]
        private delegate int GetDateFormatDelegate(
                                        uint locale,
                                        uint dwFlags,
                                        SystemTime lpDate,
                                        [MarshalAs(UnmanagedType.LPWStr)] string lpFormat,
                                        StringBuilder lpDateStr,
                                        int sbSize);

        private int getDateFormatInterceptor(
                                        uint locale,
                                        uint dwFlags,
                                        SystemTime lpDate,
                                        string lpFormat,
                                        StringBuilder lpDateStr,
                                        int sbSize)
        {

        }

public class MessagesReceiverInterface : MarshalByRefObject
{
    public void Ping()
    {
    }
}

 var channel = RemoteHooking.IpcCreateServer<MessagesReceiverInterface>(ref _channelName, WellKnownObjectMode.SingleCall);

 RemoteHooking.Inject(
  explorer.Id,
  InjectionOptions.Default | InjectionOptions.DoNotRequireStrongName,
  "ExplorerPCal.Hooks.dll", // 32-bit version (the same, because of using AnyCPU)
  "ExplorerPCal.Hooks.dll", // 64-bit version (the same, because of using AnyCPU)
  _channelName
);

 .ctor(IContext, %ArgumentList%)
void Run(IContext, %ArgumentList%)

             try
            {
                while (true)
                {
                    Thread.Sleep(500);
                    _interface.Ping();
                }
            }
            catch
            {
                _interface = null;
                // .NET Remoting will raise an exception if host is unreachable

            }

// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
</Project>

global using System;

global using static System.Console;

<ImplicitUsings>enable</ImplicitUsings>

// <auto-generated/>
global using global::System;
global using global::System.Collections.Generic;
global using global::System.IO;
global using global::System.Linq;
global using global::System.Net.Http;
global using global::System.Threading;
global using global::System.Threading.Tasks;

// <autogenerated />
global using global::System;
global using global::System.Collections.Generic;
global using global::System.IO;
global using global::System.Linq;
global using global::System.Net.Http;
global using global::System.Threading;
global using global::System.Threading.Tasks;
global using global::System.Net.Http.Json;
global using global::Microsoft.AspNetCore.Builder;
global using global::Microsoft.AspNetCore.Hosting;
global using global::Microsoft.AspNetCore.Http;
global using global::Microsoft.AspNetCore.Routing;
global using global::Microsoft.Extensions.Configuration;
global using global::Microsoft.Extensions.DependencyInjection;
global using global::Microsoft.Extensions.Hosting;
global using global::Microsoft.Extensions.Logging;

<ItemGroup>
   <Import Remove="System.Threading" />
   <Import Include="Microsoft.Extensions.Logging" />
</ItemGroup>

<ItemGroup Condition="'$(TargetFramework)' == 'net472'">
</ItemGroup>

static async IAsyncEnumerable<int> RangeAsync(int start, int count)
{
  for (int i = 0; i < count; i++)
  {
    await Task.Delay(i);
    yield return start + i;
  }
}

    [ApiController]
    [Route("[controller]")]
    public class CustomerController : ControllerBase
    {
        private readonly IDictionary<int, Customer> _customers;
        private void FillCustomerFromMemory(int countOfCustomer)
        {
            for (int CustomerId = 1; CustomerId <= countOfCustomer; CustomerId++)
            {
                _customers.Add(key: CustomerId, new Customer($"name_{CustomerId}", CustomerId));
            }
        }
        public CustomerController()
        {
            _customers = new Dictionary<int, Customer>();
            FillCustomerFromMemory(countOfCustomer : 100);
        }
        [HttpGet]
        public async Task<IEnumerable<Customer>> Get()
        {
            var output = new List<Customer>();
            while (_customers.Any(_ => _.Key % 10 == 0))
            {
                var customer = _customers.First(_ => _.Key % 10 == 0);
                output.Add(new Customer(customer.Value.Name, customer.Key));
                await Task.Delay(500);
                _customers.Remove(customer);
            }
            return output;
        }

        public class Customer
        {
            public int Id { get; private set; }

            public string Name { get; private set; }
            public Customer(string name, int id)
            {
                Name = name;
                Id = id;
            }
        }
    }

  [HttpGet]
        public async IAsyncEnumerable<Customer> Get()
        {
            while (_customers.Any(_ => _.Key % 10 == 0))
            {
                var customer = _customers.First(_ => _.Key % 10 == 0);
                yield return new Customer(customer.Value.Name, customer.Key);
                _customers.Remove(customer);
                await Task.Delay(500);
            }
        }

const int TARGET = 80;
var _httpClient = new HttpClient();
using (var response = await _httpClient.GetAsync(
    "https://localhost:7284/customer",
     HttpCompletionOption.ResponseHeadersRead))
{
    var stream = await response.Content.ReadAsStreamAsync();

    var _jsonSerializerSettings = new JsonSerializerSettings();
    var _serializer = Newtonsoft.Json.JsonSerializer.Create(_jsonSerializerSettings);

    using TextReader textReader = new StreamReader(stream);
    using JsonReader jsonReader = new JsonTextReader(textReader);

    await using (stream.ConfigureAwait(false))
    {
        await jsonReader.ReadAsync().ConfigureAwait(false);
        while (await jsonReader.ReadAsync().ConfigureAwait(false) &&
               jsonReader.TokenType != JsonToken.EndArray)
        {
            Customer customer = _serializer!.Deserialize<Customer>(jsonReader);
            if (customer.Id == TARGET)
            {
                Console.WriteLine(customer.Id + " : " + customer.Name);
                break;
            }
        }
    }
}

[HttpGet]
        public async IAsyncEnumerable<Customer> Get(CancellationToken cancellationToken)
        {
            while (!cancellationToken.IsCancellationRequested && _customers.Any(_ => _.Key % 10 == 0))
            {
                var customer = _customers.First(_ => _.Key % 10 == 0);
                yield return new Customer(customer.Value.Name, customer.Key);
                _customers.Remove(customer);
                await Task.Delay(500,cancellationToken);
            }
        }

const int TARGET = 80;
var _httpClient = new HttpClient();
var _cancelationTokenSource = new CancellationTokenSource();

using (var response = await _httpClient.GetAsync(
    "https://localhost:7284/customer",
     HttpCompletionOption.ResponseHeadersRead,
     _cancelationTokenSource.Token))
{
    var stream = await response.Content.ReadAsStreamAsync(_cancelationTokenSource.Token);

    var _jsonSerializerSettings = new JsonSerializerSettings();
    var _serializer = Newtonsoft.Json.JsonSerializer.Create(_jsonSerializerSettings);

    using TextReader textReader = new StreamReader(stream);
    using JsonReader jsonReader = new JsonTextReader(textReader);

    await using (stream.ConfigureAwait(false))
    {
        await jsonReader.ReadAsync(_cancelationTokenSource.Token).ConfigureAwait(false);
        while (await jsonReader.ReadAsync(_cancelationTokenSource.Token).ConfigureAwait(false) &&
               jsonReader.TokenType != JsonToken.EndArray)
        {
            Customer customer = _serializer!.Deserialize<Customer>(jsonReader);
            if (customer.Id == TARGET)
            {
                Console.WriteLine(customer.Id + " : " + customer.Name);
                _cancelationTokenSource.Cancel();
                break;
            }
        }
    }
}

using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Mvc;
using Kendo.DynamicLinq;
using KendoUI06Mvc.Models;
using Newtonsoft.Json;

namespace KendoUI06Mvc.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View(); // shows the page.
        }

        [HttpDelete]
        public ActionResult DeleteProduct(int id)
        {
            var item = ProductDataSource.LatestProducts.FirstOrDefault(x => x.Id == id);
            if (item == null)
                return new HttpNotFoundResult();

            ProductDataSource.LatestProducts.Remove(item);

            return Json(item);
        }

        [HttpGet]
        public ActionResult GetProducts()
        {
            var request = JsonConvert.DeserializeObject<DataSourceRequest>(
               this.Request.Url.ParseQueryString().GetKey(0)
            );

            var list = ProductDataSource.LatestProducts;
            return Json(list.AsQueryable()
                       .ToDataSourceResult(request.Take, request.Skip, request.Sort, request.Filter),
                       JsonRequestBehavior.AllowGet);
        }

        [HttpPost]
        public ActionResult PostProduct(Product product)
        {
            if (!ModelState.IsValid)
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

            var id = 1;
            var lastItem = ProductDataSource.LatestProducts.LastOrDefault();
            if (lastItem != null)
            {
                id = lastItem.Id + 1;
            }
            product.Id = id;
            ProductDataSource.LatestProducts.Add(product);

            // گرید آی دی جدید را به این صورت دریافت می‌کند
            return Json(new DataSourceResult { Data = new[] { product } });
        }

        [HttpPut] // Add it to fix this error: The requested resource does not support http method 'PUT'
        public ActionResult UpdateProduct(int id, Product product)
        {
            var item = ProductDataSource.LatestProducts
                                        .Select(
                                            (prod, index) =>
                                                new
                                                {
                                                    Item = prod,
                                                    Index = index
                                                })
                                        .FirstOrDefault(x => x.Item.Id == id);
            if (item == null)
                return new HttpNotFoundResult();


            if (!ModelState.IsValid || id != product.Id)
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

            ProductDataSource.LatestProducts[item.Index] = product;

            //Return HttpStatusCode.OK
            return new HttpStatusCodeResult(HttpStatusCode.OK);
        }
    }
}

        var productsDataSource = new kendo.data.DataSource({
            transport: {
                read: {
                    url: "@Url.Action("GetProducts","Home")",
                    dataType: "json",
                    contentType: 'application/json; charset=utf-8',
                    type: 'GET'
                },
                create: {
                    url: "@Url.Action("PostProduct","Home")",
                    contentType: 'application/json; charset=utf-8',
                    type: "POST"
                },
                update: {
                    url: function (product) {
                        return "@Url.Action("UpdateProduct","Home")/" + product.Id;
                        },
                        contentType: 'application/json; charset=utf-8',
                        type: "PUT"
                    },
                    destroy: {
                        url: function (product) {
                            return "@Url.Action("DeleteProduct","Home")/" + product.Id;
                        },
                        contentType: 'application/json; charset=utf-8',
                        type: "DELETE"
                    },
                    parameterMap: function (options) {
                        return kendo.stringify(options);
                    }
                },

• در مثال قبل پروژه به صورت Desktop و با WPF پیاده سازی شده بود ولی در این مثال با Silverlight می‌باشد؛
• در مثال قبل از UnityBootstrapper استفاده شده بود ولی در این مثال از MefBootstrapper؛
• در مثال قبل هر View در یک ماژول قرار داشت ولی در این مثال هر دو View را در یک ماژول قرار دادم؛
• در مثال قبل از Prism Libary 2.x استفاده شده بود ولی در این مثال از PrismLibrary 4.x؛
• و...

نکته : برای فهم بهتر مفاهیم، آشنایی اولیه با MEF و مفاهیمی نظیر Export و Import و AggregateCatalog و AssemblyCatalog نیاز است. در صورتی که با این مطالب آشنایی ندارید می‌توانید از (^) شروع کنید.

<UserControl 
             x:Class="Module1.Module1View1"
             xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" 
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" FlowDirection="RightToLeft" FontFamily="Tahoma">
    <StackPanel>
        <sdk:DataGrid Height="100">
            <sdk:DataGrid.Columns>
                <sdk:DataGridTextColumn Header="کد" Width="50"  />
                <sdk:DataGridTextColumn Header="عنوان" Width="200" />
                <sdk:DataGridTextColumn Header="نویسنده" Width="150"  />
            </sdk:DataGrid.Columns>
        </sdk:DataGrid>
        <Button x:Name="NextViewButton"
                Width="150"
                Height="25"
                Foreground="Red"
                Background="Blue"
                Content="لیست طبقه بندی ها" />
    </StackPanel>
</UserControl>

 [Export(typeof(Module1View1))]
    public partial class Module1View1 : UserControl
    {
        [Import]
        public IRegionManager TheRegionManager { private get; set; }

        public Module1View1()
        {
            InitializeComponent();

            NextViewButton.Click += NextViewButton_Click;
        }

        void NextViewButton_Click(object sender, RoutedEventArgs e)
        {
            TheRegionManager.RequestNavigate
            (
                "MyRegion1",
                new Uri("Module1View2", UriKind.Relative),
                a => { }
            );
        }
    }

<UserControl 
             xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"  x:Class="Module1.Module1View2"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" FlowDirection="RightToLeft" FontFamily="Tahoma">
    <StackPanel>
        <sdk:DataGrid Height="100">
            <sdk:DataGrid.Columns>
                <sdk:DataGridTextColumn Header="کد" Width="150"/>
                <sdk:DataGridTextColumn Header="عنوان" Width="150"/>                
            </sdk:DataGrid.Columns>
        </sdk:DataGrid>
        <Button x:Name="NextViewButton"
                Width="150"
                Height="25"
                Foreground="Green"
                Background="Yellow"
                Content="لیست کتاب ها" />
    </StackPanel>
</UserControl>

using Microsoft.Practices.Prism.Regions;
using System;
using System.ComponentModel.Composition;
using System.Windows;
using System.Windows.Controls;

namespace Module1
{
    [Export]
    public partial class Module1View2 : UserControl
    {
        IRegion _region1;

        [ImportingConstructor]
        public Module1View2( [Import] IRegionManager regionManager )
        {
            InitializeComponent();
         
            ViewModel viewModel = new ViewModel();
            DataContext = viewModel;

            viewModel.ShouldNavigateFromCurrentViewEvent += () => { return true; };

            _region1 = regionManager.Regions["MyRegion1"];

            NextViewButton.Click += NextViewButton_Click;
        }

        void NextViewButton_Click( object sender, RoutedEventArgs e )
        {
            _region1.RequestNavigate
            (
                new Uri( "Module1View1", UriKind.Relative ),
                a => { }
            );
        }
    }
}

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.ComponentModel.Composition;
using Microsoft.Practices.Prism.Regions;

namespace Module1
{
    public class ViewModel : IConfirmNavigationRequest
    {       
        public event Func<bool> ShouldNavigateFromCurrentViewEvent;      

        public bool IsNavigationTarget( NavigationContext navigationContext )
        {
            return true;
        }

        public void OnNavigatedTo( NavigationContext navigationContext )
        {

        }

        public void OnNavigatedFrom( NavigationContext navigationContext )
        {

        }         

        public void ConfirmNavigationRequest( NavigationContext navigationContext, Action<bool> continuationCallback )
        {
            bool shouldNavigateFromCurrentViewFlag = false;

            if ( ShouldNavigateFromCurrentViewEvent != null )
                shouldNavigateFromCurrentViewFlag = ShouldNavigateFromCurrentViewEvent();

            continuationCallback( shouldNavigateFromCurrentViewFlag );
        }    
    }
}

using Microsoft.Practices.Prism.MefExtensions.Modularity;
using Microsoft.Practices.Prism.Modularity;
using Microsoft.Practices.Prism.Regions;
using System.ComponentModel.Composition;

namespace Module1
{
    [ModuleExport(typeof(Module1Impl))]
    public class Module1Impl : IModule
    {       
        [Import]
        public IRegionManager TheRegionManager { private get; set; }     

        public void Initialize()
        {
            TheRegionManager.RegisterViewWithRegion("MyRegion1", typeof(Module1View1));

            TheRegionManager.RegisterViewWithRegion("MyRegion1", typeof(Module1View2));
        }
    }
}

<UserControl x:Class="NavigationViaViewModel.Shell"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://www.codeplex.com/prism" FlowDirection="RightToLeft" FontFamily="Tahoma">

    <Grid x:Name="LayoutRoot"
          Background="White">
        <TextBlock Text="لیست کتاب‌ها به همراه طبقه بندی آن ها"
                   FontSize="19"
                   Foreground="Black"
                   HorizontalAlignment="Center"
                   VerticalAlignment="Top" />
        <ContentControl HorizontalAlignment="Center"
                        VerticalAlignment="Center"
                        prism:RegionManager.RegionName="MyRegion1" />
    </Grid>
</UserControl>

using Microsoft.Practices.Prism.MefExtensions;
using Microsoft.Practices.Prism.Modularity;
using System.ComponentModel.Composition.Hosting;
using System.Windows;

namespace NavigationViaViewModel
{
    public class TheBootstrapper : MefBootstrapper
    {
        protected override void InitializeShell()
        {
            base.InitializeShell();

            Application.Current.RootVisual = (UIElement)Shell;
        }

        protected override DependencyObject CreateShell()
        {
            return Container.GetExportedValue<Shell>();
        }

        protected override void ConfigureAggregateCatalog()
        {
            base.ConfigureAggregateCatalog();        
            AggregateCatalog.Catalogs.Add(new AssemblyCatalog(this.GetType().Assembly));
        }

        protected override IModuleCatalog CreateModuleCatalog()
        {
            ModuleCatalog moduleCatalog = new ModuleCatalog();
    
            moduleCatalog.AddModule
            (
                new ModuleInfo
                {
                    InitializationMode = InitializationMode.WhenAvailable,
                    Ref = "Module1.xap",
                    ModuleName = "Module1Impl",
                    ModuleType = "Module1.Module1Impl, Module1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
                }
            );

            return moduleCatalog;
        }
    }
}