mkdir testapp
cd testapp
touch index.js
npm init
npm i express --save

"scripts": {
    "start": "node index"
  }

const express = require('express')
const app = express()

const PORT = 3000;

app.get('/', function (req, res) {
  res.send('Hello World')
})

app.listen(PORT, function () {
  console.log(`listening on port ${PORT}!`)
})

docker run -d -p 3030:3000 -v $(pwd):/var/www -w "/var/www" node npm start

docker ps

docker exec -it 6003 bash

cat index.js

docker stop 6003

docker ps -a

docker rm -v 6003

for (int i = 0; i < 2000; i++)
{
    Pupil pupil = GetNewPupil();
    db.Pupils.Add(pupil);
}
db.SaveChanges();

var list = new List<Pupil>();

for (int i = 0; i < 2000; i++)
{
    Pupil pupil = GetNewPupil();
    list.Add(pupil);
}

db.Pupils.AddRange(list);
db.SaveChanges();

db.Configuration.AutoDetectChangesEnabled = false;

string city = "New York";

List<School> schools = db.Schools
    .AsNoTracking()
    .Where(s => s.City == city)
    .Take(100)
    .ToList();

 public class CustomManifestTokenResolver : IManifestTokenResolver
{
    public string ResolveManifestToken(DbConnection connection)
    {
        return "2014";
    }
}

 public class CustomDbConfiguration : DbConfiguration
{
    public CustomDbConfiguration()
    {
        SetManifestTokenResolver(new CustomManifestTokenResolver());
    }
}

MultipleActiveResultSets=True;

  <system.webServer>
    <security>
      <authentication>
        <anonymousAuthentication enabled="true" />
        <windowsAuthentication enabled="true" />
      </authentication>
    </security>
  </system.webServer>

{
  "iisSettings": {
    "windowsAuthentication": true,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:3381/",
      "sslPort": 0
    }
  }
}

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified"/>
    </handlers>
    <aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" 
            stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" 
            forwardWindowsAuthToken="true"/>
  </system.webServer>
</configuration>

namespace ASPNETCore2WindowsAuthentication
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var host = new WebHostBuilder()
                                     .UseKestrel()
                                     .UseContentRoot(Directory.GetCurrentDirectory())
                                     .UseStartup<Startup>()
                                     .UseHttpSys(options => // Just for local tests without IIS, Or self-hosted scenarios on Windows ...
                                     {
                                         options.Authentication.Schemes =
                                              AuthenticationSchemes.Negotiate | AuthenticationSchemes.NTLM;
                                         options.Authentication.AllowAnonymous = true;
                                         //options.UrlPrefixes.Add("http://+:80/");
                                     })
                                     .Build();
            host.Run();
        }
    }
}

namespace ASPNETCore2WindowsAuthentication
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var host = new WebHostBuilder()
                                     .UseKestrel()
                                     .UseContentRoot(Directory.GetCurrentDirectory())
                                     .UseIISIntegration()
                                     .UseDefaultServiceProvider((context, options) =>
                                     {
                                         options.ValidateScopes = context.HostingEnvironment.IsDevelopment();
                                     })
                                     .UseStartup<Startup>()
                                     .Build();
            host.Run();
        }
    }
}

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();

            services.Configure<IISOptions>(options =>
            {
                // Sets the HttpContext.User
                // Note: Windows Authentication must also be enabled in IIS for this to work.
                options.AutomaticAuthentication = true;
                options.ForwardClientCertificate = true;
            });
            
            services.AddAuthentication(options =>
            {
                // for both windows and anonymous authentication
                options.DefaultChallengeScheme = IISDefaults.AuthenticationScheme;
            });
        }

        private string authInfo()
        {
            var claims = new StringBuilder();
            if (User.Identity is ClaimsIdentity claimsIdentity)
            {
                claims.Append("Your claims: \n");
                foreach (var claim in claimsIdentity.Claims)
                {
                    claims.Append(claim.Type + ", ");
                    claims.Append(claim.Value + "\n");
                }
            }

            return $"IsAuthenticated: {User.Identity.IsAuthenticated}; Identity.Name: {User.Identity.Name}; WindowsPrincipal: {(User is WindowsPrincipal)}\n{claims}";
        }

namespace ASPNETCore2WindowsAuthentication.Controllers
{
    public class HomeController : Controller
    {
        public IActionResult Index()
        {
            return View();
        }

        [Authorize]
        public IActionResult Windows()
        {
            return Content(authInfo());
        }

        private string authInfo()
        {
            var claims = new StringBuilder();
            if (User.Identity is ClaimsIdentity claimsIdentity)
            {
                claims.Append("Your claims: \n");
                foreach (var claim in claimsIdentity.Claims)
                {
                    claims.Append(claim.Type + ", ");
                    claims.Append(claim.Value + "\n");
                }
            }

            return $"IsAuthenticated: {User.Identity.IsAuthenticated}; Identity.Name: {User.Identity.Name}; WindowsPrincipal: {(User is WindowsPrincipal)}\n{claims}";
        }

        [AllowAnonymous]
        public IActionResult Anonymous()
        {
            return Content(authInfo());
        }

        [Authorize(Roles = "Domain Admins")]
        public IActionResult ForAdmins()
        {
            return Content(authInfo());
        }

        [Authorize(Roles = "Domain Users")]
        public IActionResult ForUsers()
        {
            return Content(authInfo());
        }
    }
}

 dotnet publish

[Authorize(Roles = @"<domain>\<group>")]
//or
[Authorize(Roles = @"<domain>\<group1>,<domain>\<group2>")]

services.AddAuthorization(options =>
{
   options.AddPolicy("RequireWindowsGroupMembership", policy =>
   {
     policy.RequireAuthenticatedUser();
     policy.RequireRole(@"<domain>\<group>"));  
   }
});

 [Authorize(Policy = "RequireWindowsGroupMembership")]

[HttpGet("[action]")]
public IActionResult SomeValue()
{
    if (!User.IsInRole(@"Domain\Group")) return StatusCode(403);
    return Ok("Some Value");
}

    public class ApplicationClaimsTransformation : IClaimsTransformation
    {
        private readonly ILogger<ApplicationClaimsTransformation> _logger;

        public ApplicationClaimsTransformation(ILogger<ApplicationClaimsTransformation> logger)
        {
            _logger = logger;
        }

        public Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
        {
            if (!(principal.Identity is ClaimsIdentity identity))
            {
                return Task.FromResult(principal);
            }

            var claims = addExistingUserClaims(identity);
            identity.AddClaims(claims);

            return Task.FromResult(principal);
        }

        private IEnumerable<Claim> addExistingUserClaims(IIdentity identity)
        {
            var claims = new List<Claim>();
            var user = @"VahidPC\Vahid";
            if (identity.Name != user)
            {
                _logger.LogError($"Couldn't find {identity.Name}.");
                return claims;
            }

            claims.Add(new Claim(ClaimTypes.GivenName, user));
            return claims;
        }
    }

            services.AddScoped<IClaimsTransformation, ApplicationClaimsTransformation>();
            services.AddAuthentication(options =>
            {
                // for both windows and anonymous authentication
                options.DefaultChallengeScheme = IISDefaults.AuthenticationScheme;
            });

var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
var userName = User.FindFirstValue(ClaimTypes.Name);
var userName = User.FindFirstValue(ClaimTypes.GivenName);

> Install-Package Castle.Core
> dotnet add package Castle.Core

<Project Sdk="Microsoft.NET.Sdk.Web">
  <ItemGroup>
    <PackageReference Include="castle.core" Version="4.3.1" />
  </ItemGroup>
</Project>

using System;
using Castle.DynamicProxy;
using Microsoft.Extensions.Logging;

namespace CoreIocSample02.Utils
{
    public class ExceptionHandlingInterceptor : IInterceptor
    {
        private readonly ILogger<ExceptionHandlingInterceptor> _logger;

        public ExceptionHandlingInterceptor(ILogger<ExceptionHandlingInterceptor> logger)
        {
            _logger = logger;
        }

        public void Intercept(IInvocation invocation)
        {
            try
            {
                invocation.Proceed(); //فراخوانی متد اصلی در اینجا صورت می‌گیرد
            }
            catch (Exception ex)
            {
                _logger.LogCritical(ex, "An unhandled exception has been occurred.");
            }
        }
    }
}

        public void Run()
        {
            try
            {
                _decorated.Run();
            }
            catch (Exception ex)
            {
                _logger.LogCritical(ex, "An unhandled exception has been occurred.");
            }
        }

namespace CoreIocSample02
{
    public class Startup
    {
        private static readonly ProxyGenerator _dynamicProxy = new ProxyGenerator();

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddTransient<ITaskService, MyTaskService>();
            services.AddTransient<ExceptionHandlingInterceptor>();
            services.Decorate(typeof(ITaskService),
             (target, serviceProvider) =>
                _dynamicProxy.CreateInterfaceProxyWithTargetInterface(
                  interfaceToProxy: typeof(ITaskService),
                  target: target,
                  interceptors: serviceProvider.GetRequiredService<ExceptionHandlingInterceptor>())
            );

Value 

// Behavior 1 
object obj = null;
bool objValueEqual = obj.Equals(null);

// Behavior 2 
object obj = null;
Type objType = obj.GetType();

// Behavior 3
string str = (string)null;
bool strType = str is string;

// Behavior 4
int num = 5;
Nullable<int> nullableNum = 5;
bool typeEqual = num.GetType() == nullableNum.GetType();

// Behavior 5
Type inType = typeof(int);
Type nullableIntType = typeof(Nullable<int>);
bool typeEqual = inType == nullableIntType;

        static void Main(string[] args)
        {
            Console.WriteLine(Method(null));
            Console.ReadLine();
        }
        private static string Method(object obj)
        {
            return "Object parameter";
        }
        private static string Method(string str)
        {
            return "String parameter";
        }

var rounded = Math.Round(1.5); // 2
var rounded = Math.Round(2.5); // 2

var rounded = Math.Round(2.5, MidpointRounding.ToEven); // 2
var rounded = Math.Round(2.5, MidpointRounding.AwayFromZero); // 3

var value = 1.4f;
var rounded = Math.Round(value + 0.1f); // 1

    public static class Config
    {
        public static bool ThrowException { get; set; } = true;
    }

    public class FailingClass
    {
        static FailingClass()
        {
            if (Config.ThrowException)
            {
                throw new InvalidOperationException();
            }
        }
    }

try
{
   var failedInstance = new FailingClass();
}
catch (TypeInitializationException) { }

Config.ThrowException = false;
var instance = new FailingClass();

public class BaseClass
{
    {
        public BaseClass()
        {
            VirtualMethod(1);
        }
        public virtual int VirtualMethod(int dividend)
        {
            return dividend / 1;
        }
    }

    public class DerivedClass : BaseClass
    {
        int divisor;
        public DerivedClass()
        {
            divisor = 1;
        }
        public override int VirtualMethod(int dividend)
        {
            return base.VirtualMethod(dividend / divisor);
        }
    }

 class Program
    {
        static void Main(string[] args)
        {
            var instance = new DerivedClass();
            var result = instance.Method();
            result = ((BaseClass)instance).Method();
            Console.WriteLine(instance + " -> " + result); // Derived Class ...  -> Method in BaseClass
            Console.ReadLine();

        }
    }

    public class BaseClass
    {
        public virtual string Method()
        {
            return "Method in BaseClass";
        }
    }

    public class DerivedClass : BaseClass
    {
        public override string ToString()
        {
            return "Derived Class ... ";
        }

        public new string Method()
        {
            return "Method in DerivedClass";
        }
    }

class Program
    {
        static void Main(string[] args)
        {
            var instance = new DerivedClass();
            var result = instance.Method(); // -> Method in DerivedClass
            result = ((IInterface)instance).Method(); // -> Method belonging to IInterface
            Console.WriteLine(result);
            Console.ReadLine();
        }
    }

    public interface IInterface
    {
        string Method();
    }

    public class DerivedClass : IInterface
    {
        public string Method()
        {
            return "Method in DerivedClass";
        }
        string IInterface.Method()
        {
            return "Method belonging to IInterface";
        }
}

private IEnumerable<int> GetEnumerable(StringBuilder log)
{
     using (var test = new Test(log))
      {
          return Enumerable.Range(1, 5);
      }
}

var log = new StringBuilder();
            
foreach (var number in GetEnumerable(log))
{
     log.AppendLine($"{number}");
}

Created
Disposed
1
2
3
4
5

 using (var test = new Test(log))
 {
     foreach (var i in Enumerable.Range(1,5))
     {
         yield return i;
     }
 }

Created
1
2
3
4
5
Disposed

CREATE TABLE accounts (
user_id INTEGER PRIMARY KEY,
balance INTEGER NOT NULL
);

INSERT INTO accounts(user_id, balance)
VALUES (1, 300);

DECLARE @amount INT;

SET @amount = (
SELECT balance
FROM accounts
WHERE user_id = 1
);

SELECT @amount as 'balance'

UPDATE accounts
SET balance =  @amount - 100
WHERE user_id = 1;

SELECT balance as 'balance after shopping'
FROM accounts
WHERE user_id = 1

var account1 =  context.Accounts.First(x => x.UserId == 1);
account1.Balance -= 100;
context.SaveChanges();

UPDATE accounts
SET balance =  balance - 100
WHERE user_id = 1;

WAITFOR TIME '13:47:00';

SET NOCOUNT, XACT_ABORT ON;

BEGIN TRAN;

DECLARE @amount INT;

SET @amount = (
 SELECT balance
 FROM accounts WITH (UPDLOCK, HOLDLOCK)
 WHERE user_id = 1
 );

SELECT @amount as 'initial user''s balance'

UPDATE accounts
SET balance =  @amount - 100
WHERE user_id = 1;

SELECT balance as 'user''s balance after shopping 1'
FROM accounts
WHERE user_id = 1;

COMMIT TRAN;

using System.ComponentModel.DataAnnotations;

namespace BlazorAsyncValidation.Shared;

public class UserDto
{
    [Required] public string Name { set; get; } = default!;
}

using BlazorAsyncValidation.Shared;
using Microsoft.AspNetCore.Mvc;

namespace BlazorAsyncValidation.Server.Controllers;

[ApiController, Route("api/[controller]/[action]")]
public class RegisterController : ControllerBase
{
    [HttpPost]
    public IActionResult IsUserNameUnique([FromBody] UserDto userModel)
    {
        if (string.Equals(userModel?.Name, "Vahid", StringComparison.OrdinalIgnoreCase))
        {
            return Ok(false);
        }

        return Ok(true);
    }
}

@page "/"

<PageTitle>Index</PageTitle>

<h2>Register</h2>

<EditForm EditContext="@EditContext" OnValidSubmit="DoSubmitAsync">
    <DataAnnotationsValidator/>
    <div class="row mb-2">
        <label class="col-form-label col-lg-2">Name:</label>
        <div class="col-lg-10">
            <InputText @bind-Value="Model.Name" class="form-control"/>
            <ValidationMessage For="@(() => Model.Name)"/>
        </div>
    </div>

    <button class="btn btn-secondary" type="submit">Submit</button>
</EditForm>

public partial class Index
{
    private const string UserValidationUrl = "/api/Register/IsUserNameUnique";

    private ValidationMessageStore? _messageStore;
    [Inject] private HttpClient HttpClient { set; get; } = default!;
    private EditContext? EditContext { set; get; }

    private UserDto Model { get; } = new();

    protected override void OnInitialized()
    {
        EditContext = new EditContext(Model);
        _messageStore = new ValidationMessageStore(EditContext);
        EditContext.OnFieldChanged += (sender, eventArgs) =>
        {
            var fieldIdentifier = eventArgs.FieldIdentifier;
            _messageStore?.Clear(fieldIdentifier);
            _ = InvokeAsync(async () =>
            {
                var errors = await OnValidateFieldAsync(fieldIdentifier.FieldName);
                if (errors?.Any() != true)
                {
                    return;
                }

                foreach (var error in errors)
                {
                    _messageStore?.Add(fieldIdentifier, error);
                }

                EditContext.NotifyValidationStateChanged();
            });
            StateHasChanged();
        };
        EditContext.OnValidationStateChanged += (sender, eventArgs) => StateHasChanged();
        EditContext.OnValidationRequested += (sender, eventArgs) => _messageStore?.Clear();
    }

    private async Task<IList<string>?> OnValidateFieldAsync(string fieldName)
    {
        switch (fieldName)
        {
            case nameof(UserDto.Name):
                var response = await HttpClient.PostAsJsonAsync(
                    UserValidationUrl,
                    new UserDto { Name = Model.Name });
                var responseContent = await response.Content.ReadAsStringAsync();
                if (string.Equals(responseContent, "false", StringComparison.OrdinalIgnoreCase))
                {
                    return new List<string>
                    {
                        $"`{Model.Name}` is in use. Please choose another name."
                    };
                }

                // TIP: It's better to use the `DntDebounceInputText` component for this case to reduce the network round-trips.

                break;
        }

        return null;
    }