14 .net core 存储库模式

蔚落 2023-03-02 10:59 24阅读 0赞

## 自定义存储库 ##

**定义Character实体**

public class Character
    { 
        public Character(string name)
        { 
            Name = name;
        }
    
        [Key]
        public Guid Id {  get; private set; } = Guid.NewGuid();
        public string Name {  get; private set; } = String.Empty;
    }

**定义存储库接口**

public interface ICharacterRepository { 
        IEnumerable<Character> ListAll ();
        void Add (Character character);
    }

**存储库的具体实现**

public class CharacterRepository : ICharacterRepository { 
        private readonly ApplicationDbContext _dbContext;
    
        public CharacterRepository (ApplicationDbContext dbContext) { 
            _dbContext = dbContext;
    }
    
        public IEnumerable<Character> ListAll () { 
            return _dbContext.Characters.AsEnumerable ();
    }
    
        public void Add (Character character) { 
            _dbContext.Characters.Add (character);
            _dbContext.SaveChanges ();
        }
    }

**注册存储库服务**

public void ConfigureServices (IServiceCollection services) { 
        // 添加数据库上下文
        services.AddDbContext<ApplicationDbContext> (options => options.UseInMemoryDatabase ("InMemoryDb"));
    
        // 注册 CharacterRepository 
    services.AddScoped<ICharacterRepository, CharacterRepository>();
    
        ...
    }

## 应用存储库 ##

**注入存储库的实例**

public class IndexModel : PageModel { 
        private readonly ICharacterRepository _characterRepository;
    
        // 依赖注入
        public IndexModel (ICharacterRepository characterRepository) { 
            _characterRepository = characterRepository;
    	}
    	
    	public IEnumerable<Character> Characters {  get; set; }
    	
    	    public void OnGet () { 
    	        PopulateCharactersIfNoneExist ()
    	
    	        Characters = _characterRepository.ListAll ();
    	}
    
        private void PopulateCharactersIfNoneExist () { 
            if (!_characterRepository.ListAll ().Any ()) { 
                _characterRepository.Add (new Character ("Darth Maul"));
                _characterRepository.Add (new Character ("Darth Vader"));
                _characterRepository.Add (new Character ("Yoda"));
                _characterRepository.Add (new Character ("Mace Windu"));
            }
        }
    }