public class LogRequestHandler : IHttpHandler

using System;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web;

namespace Async14
{
    public class LogRequestHandler : HttpTaskAsyncHandler
    {
        public override async Task ProcessRequestAsync(HttpContext context)
        {
            string url = context.Request.QueryString["rssfeedURL"];
            if (string.IsNullOrWhiteSpace(url))
            {
                context.Response.Write("Rss feed URL is not provided");
            }

            using (var webClient = new WebClient {Encoding = Encoding.UTF8})
            {
                webClient.Headers.Add("User-Agent", "LogRequestHandler 1.0");
                var rssfeed = await webClient.DownloadStringTaskAsync(url);
                context.Response.Write(rssfeed);
            }
        }

        public override bool IsReusable
        {
            get { return true; }
        }

        public override void ProcessRequest(HttpContext context)
        {
            throw new Exception("The ProcessRequest method has no implementation.");
        }
    }
}

 http://localhost:4207/LogRequestHandler.ashx?rssfeedURL=https://www.dntips.ir/feed/latestchanges

using System;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web.UI;

namespace Async14
{
    public partial class _default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            RegisterAsyncTask(new PageAsyncTask(LoadSomeData));
        }

        public async Task LoadSomeData()
        {
            using (var webClient = new WebClient { Encoding = Encoding.UTF8 })
            {
                webClient.Headers.Add("User-Agent", "LogRequest 1.0");
                var rssfeed = await webClient.DownloadStringTaskAsync("url");

                //listcontacts.DataSource = rssfeed;
            }
        }
    }
}

 <%@ Page Language="C#" AutoEventWireup="true"
Async="true"
  CodeBehind="default.aspx.cs" Inherits="Async14._default" %>

D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef
                     _/\__
               ---==/    \\
         ___  ___   |.    \|\
        | __|| __|  |  )   \\\
        | _| | _|   \_/ |  //|\\
        |___||_|       /   \\\/\\
Entity Framework .NET Core CLI Commands 1.0.0-preview2-21431
Usage: dotnet ef [options] [command]
Options:
  -h|--help                      Show help information
  -v|--verbose                   Enable verbose output
  --version                      Show version information
  --assembly <ASSEMBLY>          The assembly file to load.
  --startup-assembly <ASSEMBLY>  The assembly file containing the startup class.
  --data-dir <DIR>               The folder used as the data directory (defaults to current working directory).
  --project-dir <DIR>            The folder used as the project directory (defaults to current working directory).
  --content-root-path <DIR>      The folder used as the content root path for the application (defaults to application base directory).
  --root-namespace <NAMESPACE>   The root namespace of the target project (defaults to the project assembly name).
Commands:
  database    Commands to manage your database
  dbcontext   Commands to manage your DbContext types
  migrations  Commands to manage your migrations
Use "dotnet ef [command] --help" for more information about a command.

 D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef migrations add InitialDatabase

 D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef database update
Applying migration '13950526050417_InitialDatabase'.
Done.

using System.Collections.Generic;
using System.Linq;
using Core1RtmEmptyTest.Entities;
using Microsoft.Extensions.DependencyInjection;

namespace Core1RtmEmptyTest.Migrations
{
    public static class ApplicationDbContextSeedData
    {
        public static void SeedData(this IServiceScopeFactory scopeFactory)
        {
            using (var serviceScope = scopeFactory.CreateScope())
            {
                var context = serviceScope.ServiceProvider.GetService<ApplicationDbContext>();
                if (!context.Persons.Any())
                {
                    var persons = new List<Person>
                    {
                        new Person
                        {
                            FirstName = "Admin",
                            LastName = "User"
                        }
                    };
                    context.AddRange(persons);
                    context.SaveChanges();
                }
            }
        }
    }
}

public void Configure(IServiceScopeFactory scopeFactory)
{
    scopeFactory.SeedData();

public void ConfigureServices(IServiceCollection services)
{
   services.AddDbContext<ApplicationDbContext>(ServiceLifetime.Scoped);

namespace Core1RtmEmptyTest.Entities
{
    public class Person
    {
        public int PersonId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public int Age { get; set; }
    }
}

 An unhandled exception occurred while processing the request.
SqlException: Invalid column name 'Age'.

D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef migrations add v2
D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef database update

 D:\Prog\1395\Core1RtmEmptyTest\src\Core1RtmEmptyTest>dotnet ef migrations script -o v2.sql

public Configuration()
{
   AutomaticMigrationsEnabled = true;
}

using Core1RtmEmptyTest.Entities;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;

namespace Core1RtmEmptyTest.Migrations
{
    public static class DbInitialization
    {
        public static void Initialize(this IServiceScopeFactory scopeFactory)
        {
            using (var serviceScope = scopeFactory.CreateScope())
            {
                var context = serviceScope.ServiceProvider.GetService<ApplicationDbContext>();
                // Applies any pending migrations for the context to the database.
                // Will create the database if it does not already exist.
                context.Database.Migrate();
            }
        }
    }
}

document.cookie = 'mySecondCookie=mySecondValue; path=/'

// ...

@*@attribute [Authorize]*@


@code
{
    [CascadingParameter] public Task<AuthenticationState> AuthenticationState { get; set; }

    protected override async Task OnInitializedAsync()
    {
        var authenticationState = await AuthenticationState;
        if (!authenticationState.User.Identity.IsAuthenticated)
        {
            var uri = new Uri(NavigationManager.Uri);
            NavigationManager.NavigateTo($"/identity/account/login?returnUrl={uri.LocalPath}");
        }
        // ...

namespace BlazorServer.Common
{
    public static class ConstantRoles
    {
        public const string Admin = nameof(Admin);
        public const string Customer = nameof(Customer);
        public const string Employee = nameof(Employee);
    }
}

{
  "AdminUserSeed": {
    "UserName": "vahid@dntips.ir",
    "Password": "123@456#Pass",
    "Email": "vahid@dntips.ir"
  }
}

namespace BlazorServer.Models
{
    public class AdminUserSeed
    {
        public string UserName { get; set; }
        public string Password { get; set; }
        public string Email { get; set; }
    }
}

namespace BlazorServer.App
{
    public class Startup
    {

        public IConfiguration Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddOptions<AdminUserSeed>().Bind(Configuration.GetSection("AdminUserSeed"));
            // ...

using System;
using System.Linq;
using System.Threading.Tasks;
using BlazorServer.Common;
using BlazorServer.DataAccess;
using BlazorServer.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;

namespace BlazorServer.Services
{
    public class IdentityDbInitializer : IIdentityDbInitializer
    {
        private readonly ApplicationDbContext _dbContext;
        private readonly UserManager<IdentityUser> _userManager;
        private readonly RoleManager<IdentityRole> _roleManager;
        private readonly IOptions<AdminUserSeed> _adminUserSeedOptions;

        public IdentityDbInitializer(
            ApplicationDbContext dbContext,
            UserManager<IdentityUser> userManager,
            RoleManager<IdentityRole> roleManager,
            IOptions<AdminUserSeed> adminUserSeedOptions)
        {
            _dbContext = dbContext ?? throw new ArgumentNullException(nameof(dbContext));
            _roleManager = roleManager ?? throw new ArgumentNullException(nameof(roleManager));
            _userManager = userManager ?? throw new ArgumentNullException(nameof(userManager));
            _adminUserSeedOptions = adminUserSeedOptions ?? throw new ArgumentNullException(nameof(adminUserSeedOptions));
        }

        public async Task SeedDatabaseWithAdminUserAsync()
        {
            if (_dbContext.Roles.Any(role => role.Name == ConstantRoles.Admin))
            {
                return;
            }

            await _roleManager.CreateAsync(new IdentityRole(ConstantRoles.Admin));
            await _roleManager.CreateAsync(new IdentityRole(ConstantRoles.Customer));
            await _roleManager.CreateAsync(new IdentityRole(ConstantRoles.Employee));

            await _userManager.CreateAsync(
                new IdentityUser
                {
                    UserName = _adminUserSeedOptions.Value.UserName,
                    Email = _adminUserSeedOptions.Value.Email,
                    EmailConfirmed = true
                },
                _adminUserSeedOptions.Value.Password);

            var user = await _dbContext.Users.FirstAsync(u => u.Email == _adminUserSeedOptions.Value.Email);
            await _userManager.AddToRoleAsync(user, ConstantRoles.Admin);
        }
    }
}

namespace BlazorServer.App
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped<IIdentityDbInitializer, IdentityDbInitializer>();
            // ...

using System;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Polly;

namespace BlazorServer.DataAccess.Utils
{
    public static class MigrationHelpers
    {
        public static void MigrateDbContext<TContext>(
                this IServiceProvider serviceProvider,
                Action<IServiceProvider> postMigrationAction
                ) where TContext : DbContext
        {
            using var scope = serviceProvider.CreateScope();
            var scopedServiceProvider = scope.ServiceProvider;
            var logger = scopedServiceProvider.GetRequiredService<ILogger<TContext>>();
            using var context = scopedServiceProvider.GetService<TContext>();

            logger.LogInformation($"Migrating the DB associated with the context {typeof(TContext).Name}");

            var retry = Policy.Handle<Exception>().WaitAndRetry(new[]
                {
                    TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(15)
                });

            retry.Execute(() =>
                {
                    context.Database.Migrate();
                    postMigrationAction(scopedServiceProvider);
                });

            logger.LogInformation($"Migrated the DB associated with the context {typeof(TContext).Name}");
        }
    }
}

public static void Main(string[] args)
{
    var host = CreateHostBuilder(args).Build();
    host.Services.MigrateDbContext<ApplicationDbContext>(
     scopedServiceProvider =>
            scopedServiceProvider.GetRequiredService<IIdentityDbInitializer>()
                                 .SeedDatabaseWithAdminUserAsync()
                                 .GetAwaiter()
                                 .GetResult()
    );
    host.Run();
}

@attribute [Authorize(Roles = ConstantRoles.Admin)]

    protected override async Task OnInitializedAsync()
    {
        var authenticationState = await AuthenticationState;
        if (!authenticationState.User.Identity.IsAuthenticated ||
            !authenticationState.User.IsInRole(ConstantRoles.Admin))
        {
            var uri = new Uri(NavigationManager.Uri);
            NavigationManager.NavigateTo($"/identity/account/login?returnUrl={uri.LocalPath}");
        }

• دوره "معرفی SignalR و ارتباطات بلادرنگ"
  
• نگاهی به اجزای تعاملی Twitter Bootstrap 
  

   using System;
   using System.Globalization;
   using System.Linq;

    public static DateTime PersianDateToGregorianDate(string pDate)
    {
        var dateParts = pDate.Split(new[] { '/' }).Select(d => int.Parse(d)).ToArray();
        var hour = 0;
        var min = 0;
        var seconds = 0;
        return new DateTime(dateParts[0], dateParts[1], dateParts[2],
                            hour, min, seconds, new PersianCalendar());
    }

class NumberTypeOfTypeScript { 
    MyFunction()
    {
        var p: number; 
        p = 1;
        var q = 2;
        var r = 3.33;
        alert("Value of P=" + p + "  Value of q=" + q + " Value of r=" + r);           
    }
}

window.onload = () =>{ 
    var value = new NumberTypeOfTypeScript();
    value.MyFunction();
}

<!DOCTYPE html> 
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="utf-8" />
    <title>TypeScript HTML App</title>
    <link rel="stylesheet" href="app.css" type="text/css" />
    <script src="app.js"></script>
</head>
<body>
    <h1>Number Type in TypeScript</h1> 
    <div id="content"/>
</body>
</html>

class StringTypeOfTypeScript { 
    Myfunction() { 
      var  s: string;
      s="TypeScript"
      var empty = "";
      var abc = "abc";
      alert("Value of s="+ s+" Empty string="+ empty+" Value of abc ="+abc) ;     
    }
}
window.onload = () =>{ 
    var value = new StringTypeOfTypeScript();
    value.Myfunction();
}

var StringTypeOfTypeScript = (function () {
    function StringTypeOfTypeScript() { }
    StringTypeOfTypeScript.prototype.Myfunction = function () {
        var s;
        s = "TypeScript";
        var empty = "";
        var abc = "abc";
        alert("Value of s=" + s + " Empty string=" + empty + " Value of abc =" + abc);
    };
    return StringTypeOfTypeScript;
})();
window.onload = function () {
    var value = new StringTypeOfTypeScript();
    value.Myfunction();
};

class booleanTypeofTypeScript { 
    MyFunction() {
        var lie: bool;        
        lie = false;
        var a = 12;
        if (typeof (lie) == "boolean" && typeof (a) == "boolean") {
            alert("Both is boolean type");
        }

        if (typeof (lie) == "boolean" && typeof (a) != "boolean") {
            alert("lie is boolean type and a is not!") 
        }
        else { 
            alert("a is boolean type and lie is not!");
        }
    }     
}

window.onload =()=> { 
    var access = new booleanTypeofTypeScript();
    access.MyFunction();
 }

var booleanTypeofTypeScript = (function () {
    function booleanTypeofTypeScript() { }
    booleanTypeofTypeScript.prototype.MyFunction = function () {
        var lie;
        lie = false;
        var a = 12;
        if(typeof (lie) == "boolean" && typeof (a) == "boolean") {
            alert("Both is boolean type");
        }
        if(typeof (lie) == "boolean" && typeof (a) != "boolean") {
            alert("lie is boolean type and a is not!");
        } else {
            alert("a is boolean type and lie is not!");
        }
    };
    return booleanTypeofTypeScript;
})();
window.onload = function () {
    var access = new booleanTypeofTypeScript();
    access.MyFunction();
};

class NullTypeinTypeScript { 
    MyFunction() { 
        var p: number = null;
        var x = null;
        if (p== null) {
            alert("p has null value!");
        }
        else { alert("p has a value"); }
    }
}
window.onload = () =>{ 
    var value = new NullTypeinTypeScript();
    value.MyFunction();
}

var NullTypeinTypeScript = (function () {
    function NullTypeinTypeScript() { }
    NullTypeinTypeScript.prototype.MyFunction = function () {
        var p = null;
        var x = null;
        if(p == null) {
            alert("p has null value!");
        } else {
            alert("p has a value");
        }
    };
    return NullTypeinTypeScript;
})();
window.onload = function () {
    var value = new NullTypeinTypeScript();
    value.MyFunction();
};

class UndefinedTypeOfTypeScript { 
    Myfunction() { 
        var p: number;
        var x = undefined;
        if (p == undefined && x == undefined) {
            alert("p and x is undefined");
        }
        else { alert("p and c cannot undefined"); }
    }
}
window.onload = () =>{ 
    var value = new UndefinedTypeOfTypeScript();
    value.Myfunction();
}

var UndefinedTypeOfTypeScript = (function () {
    function UndefinedTypeOfTypeScript() { }
    UndefinedTypeOfTypeScript.prototype.Myfunction = function () {
        var p;
        var x = undefined;
        if(p == undefined && x == undefined) {
            alert("p and x is undefined");
        } else {
            alert("p and c cannot undefined");
        }
    };
    return UndefinedTypeOfTypeScript;
})();
window.onload = function () {
    var value = new UndefinedTypeOfTypeScript();
    value.Myfunction();
};