@Directive({
  selector: "[isVisibleForAuthUser]"
})
export class IsVisibleForAuthUserDirective implements OnInit, OnDestroy {
  constructor(private elem: ElementRef, private authService: AuthService) { }

@Directive({
selector: "[hasAuthUserViewPermission]"
})
export class HasAuthUserViewPermissionDirective implements OnInit, OnDestroy {

  constructor(
  private templateRef: TemplateRef<any>,
  private viewContainer: ViewContainerRef,
  private authService: AuthService
) { }

<div *hasAuthUserViewPermission="['Admin','User']">
    *hasAuthUserViewPermission="['Admin','User']"
</div>

 this.viewContainer.createEmbeddedView(this.templateRef);

 this.viewContainer.clear();

import { Directive, Input, OnDestroy, OnInit, TemplateRef, ViewContainerRef } from "@angular/core";
import { Subscription } from "rxjs/Subscription";

import { AuthService } from "./../../core/services/auth.service";

@Directive({
  selector: "[hasAuthUserViewPermission]"
})
export class HasAuthUserViewPermissionDirective implements OnInit, OnDestroy {
  private isVisible = false;
  private requiredRoles: string[] | null = null;
  private subscription: Subscription | null = null;

  @Input()
  set hasAuthUserViewPermission(roles: string[] | null) {
    this.requiredRoles = roles;
  }

  // Note, if you don't place the * in front, you won't be able to inject the TemplateRef<any> or ViewContainerRef into your directive.
  constructor(
    private templateRef: TemplateRef<any>,
    private viewContainer: ViewContainerRef,
    private authService: AuthService
  ) { }

  ngOnInit() {
    this.subscription = this.authService.authStatus$.subscribe(status => this.changeVisibility(status));
    this.changeVisibility(this.authService.isAuthUserLoggedIn());
  }

  ngOnDestroy(): void {
    if (this.subscription) {
      this.subscription.unsubscribe();
    }
  }

  private changeVisibility(status: boolean) {
    const isInRoles = !this.requiredRoles ? true : this.authService.isAuthUserInRoles(this.requiredRoles);
    if (isInRoles && status) {
      if (!this.isVisible) {
        this.viewContainer.createEmbeddedView(this.templateRef);
        this.isVisible = true;
      }
    } else {
      this.isVisible = false;
      this.viewContainer.clear();
    }
  }
}

import { HasAuthUserViewPermissionDirective } from "./directives/has-auth-user-view-permission.directive";

@NgModule({
  declarations: [
    HasAuthUserViewPermissionDirective
  ],
  exports: [
    HasAuthUserViewPermissionDirective
  ]
})
export class SharedModule {}

import { SharedModule } from "../shared/shared.module";
@NgModule({
  imports: [
    SharedModule
  ]
})
export class DashboardModule { }

<div *hasAuthUserViewPermission="">
    *hasAuthUserViewPermission=""
</div>

<div *hasAuthUserViewPermission="['Admin','User']">
    *hasAuthUserViewPermission="['Admin','User']"
</div>

 static T Add<T>(T left, T right) where T : INumber<T> => left + right;

public readonly struct Int32 : 
  IComparable, 
  IComparable<int>, 
  IConvertible, 
  IEquatable<int>, 
  IFormattable, 
  IParsable<int>, 
  ISpanFormattable, 
  ISpanParsable<int>, 
  IAdditionOperators<int, int, int>, 
  IAdditiveIdentity<int, int>, 
  IBinaryInteger<int>, 
  IBinaryNumber<int>, 
  IBitwiseOperators<int, int, int>, 
  IComparisonOperators<int, int, bool>, 
  IEqualityOperators<int, int, bool>, 
  IDecrementOperators<int>, 
  IDivisionOperators<int, int, int>, 
  IIncrementOperators<int>, 
  IModulusOperators<int, int, int>, 
  IMultiplicativeIdentity<int, int>, 
  IMultiplyOperators<int, int, int>, 
  INumber<int>, 
  INumberBase<int>, 
  ISubtractionOperators<int, int, int>, 
  IUnaryNegationOperators<int, int>, 
  IUnaryPlusOperators<int, int>, 
  IShiftOperators<int, int, int>, 
  IMinMaxValue<int>, 
  ISignedNumber<int>

public interface INumber<TSelf> : 
IComparable, 
IComparable<TSelf>, 
IEquatable<TSelf>, 
IFormattable, 
IParsable<TSelf>, 
ISpanFormattable, 
ISpanParsable<TSelf>, 
IAdditionOperators<TSelf, TSelf, TSelf>, 
IAdditiveIdentity<TSelf, TSelf>, 
IComparisonOperators<TSelf, TSelf, bool>, 
IEqualityOperators<TSelf, TSelf, bool>, 
IDecrementOperators<TSelf>, 
IDivisionOperators<TSelf, TSelf, TSelf>, 
IIncrementOperators<TSelf>, 
IModulusOperators<TSelf, TSelf, TSelf>, 
IMultiplicativeIdentity<TSelf, TSelf>, 
IMultiplyOperators<TSelf, TSelf, TSelf>, 
INumberBase<TSelf>, 
ISubtractionOperators<TSelf, TSelf, TSelf>, 
IUnaryNegationOperators<TSelf, TSelf>, 
IUnaryPlusOperators<TSelf, TSelf> where TSelf : INumber<TSelf>?

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

public record User
{
   public string Name { set; get; }
}

var user = new User();
user.Name = "User 1";

public record User(string Name);

var user = new User("User 1");
// Error: Init-only property or indexer 'User.Name' can only be assigned
// in an object initializer, or on 'this' or 'base' in an instance constructor
// or an 'init' accessor. [CS9Features]csharp(CS8852)
user.Name = "User 1";

public record User(string Name);

using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Text;
using CS9Features;

public class User : IEquatable<User>
{
 protected virtual Type EqualityContract
 {
  [System.Runtime.CompilerServices.NullableContext(1)]
  [CompilerGenerated]
  get
  {
   return typeof(User);
  }
 }

 public string Name
 {
  get;
  set/*init*/;
 }

 public User(string Name)
 {
  this.Name = Name;
  base..ctor();
 }

 public override string ToString()
 {
  StringBuilder stringBuilder = new StringBuilder();
  stringBuilder.Append("User");
  stringBuilder.Append(" { ");
  if (PrintMembers(stringBuilder))
  {
   stringBuilder.Append(" ");
  }
  stringBuilder.Append("}");
  return stringBuilder.ToString();
 }

 protected virtual bool PrintMembers(StringBuilder builder)
 {
  builder.Append("Name");
  builder.Append(" = ");
  builder.Append((object?)Name);
  return true;
 }

 [System.Runtime.CompilerServices.NullableContext(2)]
 public static bool operator !=(User? r1, User? r2)
 {
  return !(r1 == r2);
 }

 [System.Runtime.CompilerServices.NullableContext(2)]
 public static bool operator ==(User? r1, User? r2)
 {
  return (object)r1 == r2 || (r1?.Equals(r2) ?? false);
 }

 public override int GetHashCode()
 {
  return EqualityComparer<Type>.Default.GetHashCode(EqualityContract) * -1521134295 + EqualityComparer<string>.Default.GetHashCode(Name);
 }

 public override bool Equals(object? obj)
 {
  return Equals(obj as User);
 }

 public virtual bool Equals(User? other)
 {
  return (object)other != null && EqualityContract == other!.EqualityContract && EqualityComparer<string>.Default.Equals(Name, other!.Name);
 }

 public virtual User <Clone>$()
 {
  return new User(this);
 }

 protected User(User original)
 {
  Name = original.Name;
 }

 public void Deconstruct(out string Name)
 {
  Name = this.Name;
 }
}

public virtual User <Clone>$()
{
  return new User(this);
}

public record User(string Name, int Age);

var user1 = new User("User 1", 21);

var user2 = user1 with { Age = 31 };

var user1 = new User("User 1", 21);
var user2 = new User("User 1", 21);

Console.WriteLine("user1.Equals(user2) -> {0}", user1.Equals(user2));
Console.WriteLine("user1 == user2 -> {0}", user1 == user2);

user1.Equals(user2) -> True
user1 == user2 -> True

public virtual bool Equals(User? other)
{
   return (object)other != null &&
 EqualityContract == other!.EqualityContract &&
 EqualityComparer<string>.Default.Equals(Name, other!.Name) && 
EqualityComparer<int>.Default.Equals(Age, other!.Age);
}

    public record User
    {
        public string Name { get; init; }

        public User(string name)
        {
            Name = name;
        }
    }

    public record UserWithAge : User
    {
        public int Age { get; init; }

        public UserWithAge(string name, int age) : base(name)
        {
            Age = age;
        }
    }

var user1 = new User("User 1");
var user2 = new UserWithAge("User 1", 21);

Console.WriteLine("user1.Equals(user2) -> {0}", user1.Equals(user2));
Console.WriteLine("user1 == user2 -> {0}", user1 == user2);

user1.Equals(user2) -> False
user1 == user2 -> False

public abstract record Food(int Calories);
public record Milk(int C, double FatPercentage) : Food(C);

Console.WriteLine(user1.ToString());
Console.WriteLine(user2.ToString());

User { Name = User 1 }
UserWithAge { Name = User 1, Age = 21 }

public record Person(string Name, int Age);

public void Deconstruct(out string Name, out int Age)
{
  Name = this.Name;
  Age = this.Age;
}

var (name, age) = new Person("User 1", 21);

 public record Person([Required] string Name, [Range(0, 150)] int Age);

 public class PersonController
 {
   public IActionResult Index() => View();

   [HttpPost]
   public IActionResult Index(Person person)
   {
    // ...
   }
 }

class DotnetTips
{
....
}

class DotnetTips:System.Object
{
...
}

DotnetTips dotnettips=new DotnetTips("i am constructor");

1. اولین کاری که CLR انجام می‌دهد، محاسبه‌ی مقدار حافظه یا تعداد بایت‌های فیلدهای شیء مربوطه است و همچنین اشیایی که از آن‌ها مشتق شده است؛ مثل System.Object که همیشه وجود دارد. هر شیء‌ایی که بر روی حافظه‌ی Heap قرار می‌گیرد، به یک سری اعضای اضافه هم نیاز دارد که Type Object Pointer و Sync Block Index نامیده می‌شوند و CLR از آن‌ها برای مدیریت حافظه استفاده می‌کند. تعداد بایت‌های این اعضای اضافه هم با تعداد بایت‌های شیء مدنظر جمع می‌شوند.
2. طبق تعداد بایت‌های به دست آمده، یک مقدار از حافظه‌ی Heap دریافت می‌شود.
3. دو عضو اضافه که در بند شماره یک به آن اشاره کردیم، آماده سازی می‌شوند.
4. سازنده‌ی شیء صدا زده می‌شود. سازنده بر اساس نوع ورودی شما انتخاب می‌شود و در صورت ارجاع به سازنده‌های والد، ابتدا سازنده‌های والد صدا زده می‌شوند و بعد از اینکه همه‌ی سازنده‌ها صدا زده شدند، سازنده‌ی System.Object صدا زده می‌شود که هیچ کدی ندارد؛ ولی به هر حال عمل Return آن انجام می‌شود.

کار با توابع  prevmember  و  nextmember

namespace MinimalBlog.Api.Contracts;

public interface IModule
{
    IEndpointRouteBuilder RegisterEndpoints(IEndpointRouteBuilder endpoints);
}

public static class ServiceCollectionExtensions
{
    public static IServiceCollection AddApplicationServices(this IServiceCollection services,
        WebApplicationBuilder builder)
    {
        // ...

        builder.Services.AddAllModules(typeof(Program));

        return services;
    }

    private static void AddAllModules(this IServiceCollection services, params Type[] types)
    {
        // Using the `Scrutor` to add all of the application's modules at once.
        services.Scan(scan =>
            scan.FromAssembliesOf(types)
                .AddClasses(classes => classes.AssignableTo<IModule>())
                .AsImplementedInterfaces()
                .WithSingletonLifetime());
    }
}

using MinimalBlog.Api.Contracts;

namespace MinimalBlog.Api.Extensions;

public static class ModuleExtensions
{
    public static WebApplication RegisterEndpoints(this WebApplication app)
    {
        if (app == null)
        {
            throw new ArgumentNullException(nameof(app));
        }

        var modules = app.Services.GetServices<IModule>();
        foreach (var module in modules)
        {
            module.RegisterEndpoints(app);
        }

        return app;
    }
}

using MinimalBlog.Api.Extensions;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddApplicationServices(builder);

var app = builder.Build();
app.ConfigureApplication();
app.RegisterEndpoints();

app.Run();

namespace MinimalBlog.Api.Features.Authors;

public class AuthorModule : IModule
{
    public IEndpointRouteBuilder RegisterEndpoints(IEndpointRouteBuilder endpoints)
    {
        endpoints.MapGet("/api/authors", async (MinimalBlogDbContext ctx) =>
        {
            var authors = await ctx.Authors.ToListAsync();
            return authors;
        });

        endpoints.MapPost("/api/authors", async (MinimalBlogDbContext ctx, AuthorDto authorDto) =>
        {
            var author = new Author();
            author.FirstName = authorDto.FirstName;
            author.LastName = authorDto.LastName;
            author.Bio = authorDto.Bio;
            author.DateOfBirth = authorDto.DateOfBirth;

            ctx.Authors.Add(author);
            await ctx.SaveChangesAsync();

            return author;
        });

        return endpoints;
    }
}

<Project Sdk="Microsoft.NET.Sdk.Web">
  <ItemGroup>
    <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="11.0.0" />    
    <PackageReference Include="MediatR.Extensions.Microsoft.DependencyInjection" Version="10.0.1" />  
  </ItemGroup>
</Project>

public static class ServiceCollectionExtensions
{
    public static IServiceCollection AddApplicationServices(this IServiceCollection services,
        WebApplicationBuilder builder)
    {
        // ...

        builder.Services.AddMediatR(typeof(Program));
        builder.Services.AddAutoMapper(typeof(Program));

        return services;
    }
}

using AutoMapper;
using MinimalBlog.Domain.Model;

namespace MinimalBlog.Api.Features.Authors;

public class AuthorProfile : Profile
{
    public AuthorProfile()
    {
        CreateMap<AuthorDto, Author>().ReverseMap();
    }
}

@page "/demoHotel"

        <div class="col-12">
            <h4 class="text-info">Hotel Rooms</h4>
            <span>Rooms Selected - @SelectedRooms</span>
        </div>
        @foreach (var room in Rooms)
        {
            <IndividualRoom Room="room"></IndividualRoom>
        }

@code{

    int SelectedRooms;

    void RoomSelectionCounterChanged(bool isRoomSelected)
    {
        if (isRoomSelected)
        {
            SelectedRooms++;
        }
        else
        {
            SelectedRooms--;
        }
    }
    // ...
}

<input type="checkbox" @onchange="RoomCheckBoxSelectionChanged" />

@code
{
    //...

    [Parameter]
    public EventCallback<bool> OnRoomCheckBoxSelection { get; set; }

    async Task RoomCheckBoxSelectionChanged(ChangeEventArgs e)
    {
        await OnRoomCheckBoxSelection.InvokeAsync((bool)e.Value);
    }
}

@foreach (var room in Rooms)
{
    <IndividualRoom OnRoomCheckBoxSelection="RoomSelectionCounterChanged" Room="room"></IndividualRoom>
}

<div class="bg-light border p-2 col-5 offset-1 mt-2"
    @onclick="args => AmenitySelectionChanged(args, Amenity.Name)">
    <h4 class="text-secondary">Amenity - @Amenity.Id</h4>
    @Amenity.Name<br />
    @Amenity.Description<br />
</div>

@code
{
    [Parameter]
    public BlazorAmenity Amenity { get; set; }

    [Parameter]
    public EventCallback<string> OnAmenitySelection { get; set; }

    protected async Task AmenitySelectionChanged(MouseEventArgs e, string name)
    {
        await OnAmenitySelection.InvokeAsync(name);
    }
}

@onclick="args => AmenitySelectionChanged(args, Amenity.Name)"

@page "/demoHotel"

    @foreach (var amenity in AmenitiesList)
    {
      <IndividualAmenity OnAmenitySelection="AmenitySelectionChanged" Amenity="amenity"></IndividualAmenity>
    }

    <div class="col-12">
        <p class="text-secondary"> Selected Amenity : @SelectedAmenity </p>
    </div>

@code{

    string SelectedAmenity = "";

    void AmenitySelectionChanged(string amenity)
    {
        SelectedAmenity = amenity;
    }
}

 Install-Package Telegram.Bot

[HttpPost]
public async Task<IHttpActionResult> UpdateMsg(Update update)
{
  //......
}

var bot = new Telegram.Bot.TelegramBotClient("Token");
bot.SetWebhookAsync("https://Domian/api/webhook").Wait();

namespace Telegrambot.Controllers
{
    public class WebhookController : ApiController
    {
        Telegram.Bot.TelegramBotClient _bot = new Telegram.Bot.TelegramBotClient("number");
        Translator _translator = new Translator();

        [HttpPost]
        public async Task<IHttpActionResult> UpdateMsg(Update update)
        {
            if (update.Message.Text == "/start")
            {
                await _bot.SendTextMessageAsync(update.Message.From.Id, "Welcome To My Bot");
            }
            else
            {
                var translatedRequest = _translator.Translate(update.Message.Text, "Persian", "English");
                await _bot.SendTextMessageAsync(update.Message.From.Id, translatedRequest);
            }
            return Ok(update);
        }
    }
}