public interface IState
{
    void PressPlay(MP3PlayerContext context);
}

public class MP3PlayerContext
{
    public MP3PlayerContext()
    {
        this.CurrentState = new StandbyState();
    }
    
    public MP3PlayerContext(IState state)
    {
       this.CurrentState = state; 
    }
    
    public IState CurrentState { get; set; }
    
    public void Play()
    {
        this.CurrentState.PressPlay(this);
    }
}

public class StandbyState : IState
{
    public void PressPlay(MP3PlayerContext context)
    {
        context.CurrentState = new PlayingState();
    }
}

public class PlayingState : IState
{
    public void PressPlay(MP3PlayerContext context)
    {
        context.CurrentState = new StandbyState();
    }
}

• FSharpx.TypeProviders.AppSetting : متد خواندن و نوشتن (setter  و getter) را برای فایل‌های تنظیمان پروژه (Application Setting File) فراهم می‌کند.
• FSharpx.TypeProviders.Vector : برای محاسبات با ساختار‌های برداری استفاده می‌شود.
• FSharpx.TypeProviders.Machine : برای دسترسی و اعمال تغییرات در رجیستری و فایل‌های سیستمی استفاده می‌شود.
• FSharpx.TypeProviders.Xaml : با استفاده از این افزونه می‌توانیم از فایل‌های Xaml، در پروژه‌های #F استفاده کنیم و WPF Designer نرم افزار VS.Net هم برای این زبان قابل استفاده خواهد شد.
• FSharpx.TypeProviders.Regex : امکان استفاده از عبارات با قاعده را در این پروژه فراهم می‌کند.

یک مثال از عبارات با قاعده:

type PhoneRegex = Regex< @"(?<AreaCode>^\d{3})-(?<PhoneNumber>\d{3}-\d{4}$)">

PhoneRegex.IsMatch "425-123-2345"
|> should equal true

PhoneRegex().Match("425-123-2345").CompleteMatch.Value
|> should equal "425-123-2345"

PhoneRegex().Match("425-123-2345").PhoneNumber.Value
|> should equal "123-2345"

• PresentationCore
• PresentationFramework
• WindowBase
• System.Xaml

با استفاده از پنجره Package Manager Console دستور نصب زیر را اجرا کنید(آخرین نسخه این پکیج 1.8.31  و حجم آن کمتر از یک مگابایت است):

PM> Install-Package FSharpx.TypeProviders.Xaml

حال یک فایل Xaml به پروژه اضافه کنید و کد‌های زیر را در آن کپی کنید:

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WPF F# Sample By Masoud Pakdel" Height="350" Width="525">
    <Grid Name="MainGrid">
        <StackPanel Name="StackPanel1" Margin="50">
            <Button Name="Button1">Who are you?</Button>        
        </StackPanel>
    </Grid>
</Window>

open System
open System.Windows
open System.Windows.Controls
open FSharpx
 
type MainWindow = XAML<"MainWindow.xaml">
 
let loadWindow() =
    let window = MainWindow()
    window.Button1.Click.Add(fun _ ->
        MessageBox.Show("Masoud Pakdel")
        |> ignore)
    window.Root
 
[<STAThread>]
(new Application()).Run(loadWindow())
|> ignore

[<STAThread>]
(new Application()).Run(loadWindow())
|> ignore

namespace Service.Interfaces
{
    public interface IGenericService<T> 
    {
        void AddOrUpdate(T entity);
        void Delete(T entity);
        T Find(Func<T, bool> predicate);
        T GetLast(Func<T, bool> predicate);
        IList<T> GetAll();
        IList<T> GetAll(Func<T, bool> predicate);
        IList<T> GetAll(Expression<Func<T, object>> orderby);
        IList<T> GetAll(Func<T, bool> predicate, Expression<Func<T, object>> orderby);

        Task<List<T>> GetAllAsync();
        Task<List<T>> GetAllAsync(Func<T, bool> predicate);
        Task<List<T>> GetAllAsync(Expression<Func<T, object>> orderby);
        Task<List<T>> GetAllAsync(Func<T, bool> predicate, Expression<Func<T, object>> orderby);

        int Count();
        int Count(Func<T, bool> predicate);
    }
}

public interface IBookGroupService:IGenericService<BookGroup>
    {
    }

public class EFGenericService<TEntity> : IGenericService<TEntity>
         where TEntity : class
    {
        protected IUnitOfWork _uow;
        protected IDbSet<TEntity> _tEntities;

        public EFGenericService(IUnitOfWork uow)
        {
            _uow = uow;
            _tEntities = _uow.Set<TEntity>();
        }


        public void AddOrUpdate(TEntity entity)
        {
             _tEntities.AddOrUpdate(entity);
        }

        public virtual void Delete(TEntity entity)
        {
            _tEntities.Remove(entity);
        }

        public virtual TEntity Find(Func<TEntity, bool> predicate)
        {
            return _tEntities.Where(predicate).FirstOrDefault();
        }

        public virtual TEntity GetLast(Func<TEntity, bool> predicate)
        {
            return _tEntities.Where(predicate).Last();
        }


        public virtual IList<TEntity> GetAll()
        {
            return _tEntities.ToList();
        }

        public virtual IList<TEntity> GetAll(Func<TEntity, bool> predicate)
        {
            return _tEntities.Where(predicate).ToList();
        }

        public virtual IList<TEntity> GetAll(Expression<Func<TEntity, object>> @orderby)
        {
            return _tEntities.OrderBy(@orderby).ToList();
        }

        public virtual IList<TEntity> GetAll(Func<TEntity, bool> predicate, Expression<Func<TEntity, object>> @orderby)
        {
            return _tEntities.OrderBy(@orderby).Where(predicate).ToList();
        }

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

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

        public async Task<List<TEntity>> GetAllAsync(Expression<Func<TEntity, object>> @orderby)
        {
           return await Task.Run(() => _tEntities.OrderBy(@orderby).ToList());
        }

        public async Task<List<TEntity>> GetAllAsync(Func<TEntity, bool> predicate, Expression<Func<TEntity, object>> @orderby)
        {
           return await Task.Run(()=> _tEntities.OrderBy(@orderby).Where(predicate).ToList());
        }

        public virtual int Count()
        {
            return _tEntities.Count();
        }

        public virtual int Count(Func<TEntity, bool> predicate)
        {
            return _tEntities.Count(predicate);
        }
    }

public class EFBorrowService:EFGenericService<Borrow>,IBorrowService
    {
        public EFBorrowService(IUnitOfWork uow) : base(uow)
        {
        }
    }

1. توسعه پایگاه داده سیستم دسترسی مبتنی بر نقش
2. توسعه یک Customized Filter Attribute بر پایه Authorize Attribute
3. توسعه سرویس‌های مورد استفاده در Authorize Attribute
4. توسعه کنترلر Permissions: تمامی APIهایی که در جهت همگام سازی دسترسی‌ها بین کلاینت و سرور را بر عهده دارند در این کنترلر توسعه داده میشود.
5. توسعه سرویس مدیریت دسترسی در کلاینت توسط AngularJS

توسعه پایگاه داده

    public class Permission
    {
        [Key]
        public string Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public string Area { get; set; }
        public string Control { get; set; }
        public virtual ICollection<Role> Roles { get; set; }
    }

    public class Role
    {
        [Key]
        public string Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public virtual ICollection<Permission> Permissions { get; set; }
        public virtual ICollection<User> Users { get; set; }
    }

public class ApplicationUser : IdentityUser
    {
        [MaxLength(100)]
        public string FirstName { get; set; }
        [MaxLength(100)]
        public string LastName { get; set; }
        public bool IsSysAdmin { get; set; }
        public DateTime JoinDate { get; set; }

        public virtual ICollection<Role> Roles { get; set; }
    }

    public class RBACAttribute : AuthorizeAttribute
    {
        public string Area { get; set; }
        public string Control { get; set; }
        AccessControlService _AccessControl = new AccessControlService();
        public override void OnAuthorization(HttpActionContext actionContext)
        {
            var userId = HttpContext.Current.User.Identity.GetCurrentUserId();
            // If User Ticket is Not Expired
            if (userId == null || !_AccessControl.HasPermission(userId, this.Area, this.Control))
            {
                actionContext.Response = new HttpResponseMessage(HttpStatusCode.Unauthorized);
            }
        }
    }

[HttpPost]
[Route("ChangeProductStatus")]
[RBAC(Area = "products", Control = "edit")]
public async Task<HttpResponseMessage> ChangeProductStatus(StatusCodeBindingModel model)
{
// Method Body
}

using Microsoft.AspNetCore.Identity;

namespace BlazorServer.Entities
{
    public class ApplicationUser : IdentityUser
    {
        public string Name { get; set; }
    }
}

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>

namespace BlazorWasm.WebApi
{
    public class Startup
    {
        // ...

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddIdentity<ApplicationUser, IdentityRole>()
                .AddEntityFrameworkStores<ApplicationDbContext>()
                .AddDefaultTokenProviders();
  
            // ...

dotnet tool update --global dotnet-ef --version 5.0.4
dotnet build
dotnet ef migrations --startup-project ../../BlazorWasm/BlazorWasm.WebApi/ add AddNameToAppUser --context ApplicationDbContext
dotnet ef --startup-project ../../BlazorWasm/BlazorWasm.WebApi/ database update --context ApplicationDbContext

using System.ComponentModel.DataAnnotations;

namespace BlazorServer.Models
{
    public class UserRequestDTO
    {
        [Required(ErrorMessage = "Name is required")]
        public string Name { get; set; }

        [Required(ErrorMessage = "Email is required")]
        [RegularExpression("^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$",
                ErrorMessage = "Invalid email address")]
        public string Email { get; set; }

        public string PhoneNo { get; set; }

        [Required(ErrorMessage = "Password is required.")]
        [DataType(DataType.Password)]
        public string Password { get; set; }

        [Required(ErrorMessage = "Confirm password is required")]
        [DataType(DataType.Password)]
        [Compare("Password", ErrorMessage = "Password and confirm password is not matched")]
        public string ConfirmPassword { get; set; }
    }
}

    public class RegistrationResponseDTO
    {
        public bool IsRegistrationSuccessful { get; set; }

        public IEnumerable<string> Errors { get; set; }
    }

using System;
using BlazorServer.Entities;
using BlazorServer.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using System.Threading.Tasks;
using System.Linq;
using BlazorServer.Common;

namespace BlazorWasm.WebApi.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    [Authorize]
    public class AccountController : ControllerBase
    {
        private readonly SignInManager<ApplicationUser> _signInManager;
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly RoleManager<IdentityRole> _roleManager;

        public AccountController(SignInManager<ApplicationUser> signInManager,
            UserManager<ApplicationUser> userManager,
            RoleManager<IdentityRole> roleManager)
        {
            _roleManager = roleManager ?? throw new ArgumentNullException(nameof(roleManager));
            _userManager = userManager ?? throw new ArgumentNullException(nameof(userManager));
            _signInManager = signInManager ?? throw new ArgumentNullException(nameof(signInManager));
        }

        [HttpPost]
        [AllowAnonymous]
        public async Task<IActionResult> SignUp([FromBody] UserRequestDTO userRequestDTO)
        {
            var user = new ApplicationUser
            {
                UserName = userRequestDTO.Email,
                Email = userRequestDTO.Email,
                Name = userRequestDTO.Name,
                PhoneNumber = userRequestDTO.PhoneNo,
                EmailConfirmed = true
            };
            var result = await _userManager.CreateAsync(user, userRequestDTO.Password);
            if (!result.Succeeded)
            {
                var errors = result.Errors.Select(e => e.Description);
                return BadRequest(new RegistationResponseDTO { Errors = errors, IsRegistrationSuccessful = false });
            }

            var roleResult = await _userManager.AddToRoleAsync(user, ConstantRoles.Customer);
            if (!roleResult.Succeeded)
            {
                var errors = result.Errors.Select(e => e.Description);
                return BadRequest(new RegistationResponseDTO { Errors = errors, IsRegistrationSuccessful = false });
            }

            return StatusCode(201); // Created
        }
    }
}

[Route("api/[controller]/[action]")]
[ApiController]
[Authorize]

using System.ComponentModel.DataAnnotations;

namespace BlazorServer.Models
{
    public class AuthenticationDTO
    {
        [Required(ErrorMessage = "UserName is required")]
        [RegularExpression("^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$",
            ErrorMessage = "Invalid email address")]
        public string UserName { get; set; }

        [Required(ErrorMessage = "Password is required.")]
        [DataType(DataType.Password)]
        public string Password { get; set; }
    }
}

using System.Collections.Generic;

namespace BlazorServer.Models
{
    public class AuthenticationResponseDTO
    {
        public bool IsAuthSuccessful { get; set; }

        public string ErrorMessage { get; set; }

        public string Token { get; set; }

        public UserDTO UserDTO { get; set; }
    }

    public class UserDTO
    {
        public string Id { get; set; }
        public string Name { get; set; }
        public string Email { get; set; }
        public string PhoneNo { get; set; }
    }
}

namespace BlazorServer.Models
{
    public class BearerTokensOptions
    {
        public string Key { set; get; }

        public string Issuer { set; get; }

        public string Audience { set; get; }

        public int AccessTokenExpirationMinutes { set; get; }
    }
}

{
  "BearerTokens": {
    "Key": "This is my shared key, not so secret, secret!",
    "Issuer": "https://localhost:5001/",
    "Audience": "Any",
    "AccessTokenExpirationMinutes": 20
  }
}

namespace BlazorWasm.WebApi
{
    public class Startup
    {
        // ...

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

using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;
using BlazorServer.Entities;
using BlazorServer.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;

namespace BlazorServer.Services
{

    public interface ITokenFactoryService
    {
        Task<string> CreateJwtTokensAsync(ApplicationUser user);
    }

    public class TokenFactoryService : ITokenFactoryService
    {
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly BearerTokensOptions _configuration;

        public TokenFactoryService(
                UserManager<ApplicationUser> userManager,
                IOptionsSnapshot<BearerTokensOptions> bearerTokensOptions)
        {
            _userManager = userManager ?? throw new ArgumentNullException(nameof(userManager));
            if (bearerTokensOptions is null)
            {
                throw new ArgumentNullException(nameof(bearerTokensOptions));
            }
            _configuration = bearerTokensOptions.Value;
        }

        public async Task<string> CreateJwtTokensAsync(ApplicationUser user)
        {
            var signingCredentials = new SigningCredentials(
                new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration.Key)),
                SecurityAlgorithms.HmacSha256);
            var claims = await getClaimsAsync(user);
            var now = DateTime.UtcNow;
            var tokenOptions = new JwtSecurityToken(
                issuer: _configuration.Issuer,
                audience: _configuration.Audience,
                claims: claims,
                notBefore: now,
                expires: now.AddMinutes(_configuration.AccessTokenExpirationMinutes),
                signingCredentials: signingCredentials);
            return new JwtSecurityTokenHandler().WriteToken(tokenOptions);
        }

        private async Task<List<Claim>> getClaimsAsync(ApplicationUser user)
        {
            string issuer = _configuration.Issuer;
            var claims = new List<Claim>
            {
                // Issuer
                new Claim(JwtRegisteredClaimNames.Iss, issuer, ClaimValueTypes.String, issuer),
                // Issued at
                new Claim(JwtRegisteredClaimNames.Iat, DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString(), ClaimValueTypes.Integer64, issuer),
                new Claim(ClaimTypes.Name, user.Email, ClaimValueTypes.String, issuer),
                new Claim(ClaimTypes.Email, user.Email, ClaimValueTypes.String, issuer),
                new Claim("Id", user.Id, ClaimValueTypes.String, issuer),
                new Claim("DisplayName", user.Name, ClaimValueTypes.String, issuer),
            };

            var roles = await _userManager.GetRolesAsync(user);
            foreach (var role in roles)
            {
                claims.Add(new Claim(ClaimTypes.Role, role, ClaimValueTypes.String, issuer));
            }
            return claims;
        }
    }
}

namespace BlazorWasm.WebApi
{
    public class Startup
    {
        // ...

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped<ITokenFactoryService, TokenFactoryService>();
            // ...

namespace BlazorWasm.WebApi.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    [Authorize]
    public class AccountController : ControllerBase
    {
        private readonly SignInManager<ApplicationUser> _signInManager;
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly ITokenFactoryService _tokenFactoryService;

        public AccountController(
            SignInManager<ApplicationUser> signInManager,
            UserManager<ApplicationUser> userManager,
            ITokenFactoryService tokenFactoryService)
        {
            _userManager = userManager ?? throw new ArgumentNullException(nameof(userManager));
            _signInManager = signInManager ?? throw new ArgumentNullException(nameof(signInManager));
            _tokenFactoryService = tokenFactoryService;
        }

        [HttpPost]
        [AllowAnonymous]
        public async Task<IActionResult> SignIn([FromBody] AuthenticationDTO authenticationDTO)
        {
            var result = await _signInManager.PasswordSignInAsync(
                    authenticationDTO.UserName, authenticationDTO.Password,
                    isPersistent: false, lockoutOnFailure: false);
            if (!result.Succeeded)
            {
                return Unauthorized(new AuthenticationResponseDTO
                {
                    IsAuthSuccessful = false,
                    ErrorMessage = "Invalid Authentication"
                });
            }

            var user = await _userManager.FindByNameAsync(authenticationDTO.UserName);
            if (user == null)
            {
                return Unauthorized(new AuthenticationResponseDTO
                {
                    IsAuthSuccessful = false,
                    ErrorMessage = "Invalid Authentication"
                });
            }

            var token = await _tokenFactoryService.CreateJwtTokensAsync(user);
            return Ok(new AuthenticationResponseDTO
            {
                IsAuthSuccessful = true,
                Token = token,
                UserDTO = new UserDTO
                {
                    Name = user.Name,
                    Id = user.Id,
                    Email = user.Email,
                    PhoneNo = user.PhoneNumber
                }
            });
        }
    }
}

{
  "iss": "https://localhost:5001/",
  "iat": 1616396383,
  "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name": "vahid@dntips.ir",
  "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress": "vahid@dntips.ir",
  "Id": "582855fb-e95b-45ab-b349-5e9f7de40c0c",
  "DisplayName": "vahid@dntips.ir",
  "http://schemas.microsoft.com/ws/2008/06/identity/claims/role": "Admin",
  "nbf": 1616396383,
  "exp": 1616397583,
  "aud": "Any"
}

namespace BlazorWasm.WebApi
{
    public class Startup
    {
        // ...

        public void ConfigureServices(IServiceCollection services)
        {
            var bearerTokensSection = Configuration.GetSection("BearerTokens");
            services.AddOptions<BearerTokensOptions>().Bind(bearerTokensSection);
            // ...

            var apiSettings = bearerTokensSection.Get<BearerTokensOptions>();
            var key = Encoding.UTF8.GetBytes(apiSettings.Key);
            services.AddAuthentication(opt =>
            {
                opt.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                opt.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                opt.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(cfg =>
            {
                cfg.RequireHttpsMetadata = false;
                cfg.SaveToken = true;
                cfg.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ValidateAudience = true,
                    ValidateIssuer = true,
                    ValidAudience = apiSettings.Audience,
                    ValidIssuer = apiSettings.Issuer,
                    ClockSkew = TimeSpan.Zero,
                    ValidateLifetime = true
                };
            });

            // ...

namespace BlazorWasm.WebApi
{
    public class Startup
    {
        // ...

        public void ConfigureServices(IServiceCollection services)
        {
            // ...

            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = "BlazorWasm.WebApi", Version = "v1" });
                c.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme
                {
                    In = ParameterLocation.Header,
                    Description = "Please enter the token in the field",
                    Name = "Authorization",
                    Type = SecuritySchemeType.ApiKey
                });
                c.AddSecurityRequirement(new OpenApiSecurityRequirement {
                    {
                        new OpenApiSecurityScheme
                        {
                            Reference = new OpenApiReference
                            {
                                Type = ReferenceType.SecurityScheme,
                                Id = "Bearer"
                            }
                        },
                        new string[] { }
                    }
                });
            });
        }

        // ...

dotnet new webapi --minimal -o YourDirectoryPath:\YourFolderName

version: '3.1'

services:

  db:
    image: postgres
    container_name: db
    restart: always
    environment:
      POSTGRES_PASSWORD: postgres
      POSTGRES_USERNAME: postgres
      POSTGRES_DB: BloggingDb
    ports:
        - "5432:5432"
    volumes:
      - postgres_data:/data/db

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080
  
  pgadmin4:
    image: dpage/pgadmin4
    restart: always
    environment:
      PGADMIN_DEFAULT_EMAIL: pgadmin4@pgadmin.org
      PGADMIN_DEFAULT_PASSWORD: admin
      PGADMIN_CONFIG_SERVER_MODE: 'False'
    ports:
      - 5050:80
    volumes:
      - pgadmin:/var/lib/pgadmin
    depends_on:
      - db

volumes:
  postgres_data:
  pgadmin:

docker compose up -d

"ConnectionStrings": {
    "BloggingContext": "Username=postgres;Password=postgres;Server=localhost;Database=BloggingDb”
}

dotnet add package Npgsql.EntityFrameworkCore.PostgreSQL
dotnet add package Microsoft.EntityFrameworkCore
dotnet add package Microsoft.EntityFrameworkCore.Design

namespace NpgsqlAPI.Models;

public class Post
{
    public int PostId { get; set; }
    public string Title { get; set; } = null!;
    public string Content { get; set; } = null!;

    public int BlogId { get; set; }
    public Blog Blog { get; set; } = null!;
}

namespace NpgsqlAPI.Models;

public class Blog
{
    public int BlogId { get; set; }
    public string? Url { get; set; }

    public List<Post>? Posts { get; set; }
}

using Microsoft.EntityFrameworkCore;
using NpgsqlAPI.Models;

namespace NpgsqlAPI.Data;

public class BloggingContext : DbContext
{
    public BloggingContext(DbContextOptions<BloggingContext> options)
        : base(options)
    {
    }
    public DbSet<Blog> Blogs => Set<Blog>();
    public DbSet<Post

using NpgsqlAPI.Models;

namespace NpgsqlAPI.Services.Blogs;
public interface IBlogServices
{
    Task<IEnumerable<Blog>> GetList();
    Task<Blog?> Get(uint id);
    Task<uint> Add(Blog obj);
    Task AddRange(Blog[] obj);
    Task Update(Blog obj);
    Task UpdateRange(Blog[] obj);
    Task Remove(uint id);
}

using Microsoft.EntityFrameworkCore;
using NpgsqlAPI.Data;
using NpgsqlAPI.Models;

namespace NpgsqlAPI.Services.Blogs;
public sealed class BlogEFServices : IBlogServices
{
    private readonly BloggingContext _context;
    public BlogEFServices(BloggingContext context)
    {
        _context = context;
    }

    public async Task<uint> Add(Blog obj)
    {
        await _context.Blogs.AddAsync(obj);
        return (uint)await SaveChangesAsync();
    }

    public async Task AddRange(Blog[] obj)
    {
        await _context.Blogs.AddRangeAsync(obj);
        await SaveChangesAsync();
    }

    public async Task<Blog?> Get(uint id)
    {
        return await _context.Blogs.FirstOrDefaultAsync(x=>x.BlogId == id);
    }

    public async Task<IEnumerable<Blog>> GetList()
    {
       return await _context.Blogs.ToListAsync();
    }

    public async Task Remove(uint id)
    {
        var entity = await Get(id);
        _context.Blogs.Remove(entity!);
        await SaveChangesAsync();
    }

    public async Task Update(Blog obj)
    {
        _context.Blogs.Update(obj);
        await SaveChangesAsync();
    }

    public async Task UpdateRange(Blog[] obj)
    {
        _context.Blogs.UpdateRange(obj);
        await SaveChangesAsync();
    }

    private async Task<int> SaveChangesAsync()
    {
        return await _context.SaveChangesAsync();
    }
}

using System.Data;
using Microsoft.EntityFrameworkCore;
using Npgsql;
using NpgsqlAPI.Services.Blogs;
using NpgsqlAPI.Data;
using NpgsqlAPI.Models;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

string connectionString = builder.Configuration.GetConnectionString("BloggingContext")!;

builder.Services.AddDbContext<BloggingContext>(options =>
        options.UseNpgsql(connectionString));

builder.Services.AddTransient<IDbConnection>(_ => new NpgsqlConnection(connectionString));

// builder.Services.AddScoped<IBlogServices, BlogDapperServices>();
// builder.Services.AddScoped<IBlogServices, BlogEFRawQueryServices>();
builder.Services.AddScoped<IBlogServices, BlogEFServices>();

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.MapGet("/blogs", async (IBlogServices service) => await service.GetList())
.WithName("GetBlogs")
.WithOpenApi();

app.MapGet("/blogs/{id}", async (IBlogServices service, uint id) => await service.Get(id))
.WithName("GetBlog")
.WithOpenApi();

app.MapPost("/blogs", async (IBlogServices service, Blog blog) => await service.Add(blog))
.WithName("AddBlog")
.WithOpenApi();

app.MapDelete("/blogs/{id}", async (IBlogServices service, uint id) => await service.Remove(id))
.WithName("RemoveBlog")
.WithOpenApi();

app.MapPut("/blogs", async (IBlogServices service, Blog blog) => await service.Update(blog))
.WithName("UpdateBlog")
.WithOpenApi();

app.MapPut("/blogs/Bulk", async (IBlogServices service, Blog[] blogs) =>
 await service.UpdateRange(blogs))
.WithName("UpdateBulkBlog")
.WithOpenApi();

app.MapPost("/blogs/Bulk", async (IBlogServices service, Blog[] blogs) =>
 await service.AddRange(blogs))
.WithName("AddBulkBlog")
.WithOpenApi();

app.Run();

dotnet ef migrations add Init
dotnet ef database update

 IDependency dependency= new Dependency();

public class Shopper
{
   private readonly ICreditCard _creditCard;
   public Shopper(ICreditCard creditCard)
   {
      _creditCard = creditCard;
   }
}

 ICreditCard creditCard = new MasterCard();
Shopper shopper = new Shopper(creditCard);

public class Shopper
{
   public ICreditCard CreditCard { get; set; }
}

ICreditCard creditCard = new MasterCard();
Shopper shopper = new Shopper();
shopper.CreditCard = creditCard;

public interface IDependOnCreditCard
{
   void Inject(ICreditCard creditCard);
}

public class Shopper : IDependOnCreditCard
{
  private ICreditCard creditCard;
  public void Inject(ICreditCard creditCard)
  {
     this.creditCard = creditCard;
  }
}  

ICreditCard creditCard = new MasterCard();
Shopper shopper = new Shopper();
((IDependOnCreditCard)shopper).Inject(creditCard);