使用Linq到Sql和C#的存储库模式的实现示例

public class MyDbContext : DbContext
{
    public MyDbContext(DbContextOptions<MyDbContext> options)
        : base(options)
    {
    }

    public DbSet<User> Users { get; set; }
}

public interface IUserRepository
{
    Task<User> GetUserByIdAsync(int id);
    Task<List<User>> GetUsersAsync();
    Task<User> AddUserAsync(User user);
    Task<User> UpdateUserAsync(User user);
    Task DeleteUserAsync(User user);
}

public class UserRepository : IUserRepository
{
    private readonly MyDbContext _context;

    public UserRepository(MyDbContext context)
    {
        _context = context;
    }

    public async Task<User> GetUserByIdAsync(int id)
    {
        return await _context.Users.FindAsync(id);
    }

    public async Task<List<User>> GetUsersAsync()
    {
        return await _context.Users.ToListAsync();
    }

    public async Task<User> AddUserAsync(User user)
    {
        await _context.Users.AddAsync(user);
        await _context.SaveChangesAsync();
        return user;
    }

    public async Task<User> UpdateUserAsync(User user)
    {
        _context.Users.Update(user);
        await _context.SaveChangesAsync();
        return user;
    }

    public async Task DeleteUserAsync(User user)
    {
        _context.Users.Remove(user);
        await _context.SaveChangesAsync();
    }
}

public class UserController : Controller
{
    private readonly IUserRepository _userRepository;

    public UserController(IUserRepository userRepository)
    {
        _userRepository = userRepository;
    }

    public async Task<IActionResult> Index()
    {
        var users = await _userRepository.GetUsersAsync();
        return View(users);
    }

    // Other controller methods that use the _userRepository
}