（六）Service（服务层）

（一）前言

Asp.Net Core 项目中的“服务”，指的是用于扩展应用程序功能的一系列类型。在程序初始化期间，会把需要的服务类型实例添加到ServiceCollection集合中，这些服务实例将通过依赖注入提供给其他代码使用。

Service结构设计：其实服务和仓储的结构是一致的，主要是为了比较好区分。我之前见过又一个奇葩写的，仓储层写用文件夹弄的挺工整的，服务就一个文件夹都没有，找基类都找不到他的。

各文件夹介绍：这个就免了吧，和仓储的结构是一致的。我见给的大部分的项目都是一致的，就又一些特殊的不一致而已。（我这是指的是结构上哈） 

（二）Service服务创建

1、创建仓储的项目，创建文件夹这些我就不截图了。

2、引用Entity类库，Repository服务层就行了。

3、基类（BaseService、IBaseService）代码。

BaseService类

public class BaseService<TEntity> : IBaseService<TEntity> where TEntity : class, new()
    {
        //从子类(仓储中)的构造函授中传入
        protected IBaseRepository<TEntity> _IbaseRepository;
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        public async Task<bool> CreateAsync(TEntity entity)
        {
            return await _IbaseRepository.CreateAsync(entity);
        }
        /// <summary>
        /// 根据ID删除
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public async Task<bool> DeleteAsync(int ID)
        {
            return await _IbaseRepository.DeleteAsync(ID);
        }
        /// <summary>
        /// 修改
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        public async Task<bool> EditAsync(TEntity entity)
        {
            return await _IbaseRepository.EditAsync(entity);
        }
        /// <summary>
        /// 根据ID查询
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public async Task<TEntity> FindAsync(int Id)
        {
            //用户数据，不可能返回到前端去的；（我的总结是查询都用上virtual；virtual代表的是虚方法）
            return await _IbaseRepository.FindAsync(Id);
        }
        /// <summary>
        /// 根据条件查询接口
        /// </summary>
        /// <param name="func"></param>
        /// <returns></returns>
        public async Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> func)
        {
            return await _IbaseRepository.FindAsync(func);
        }
        /// <summary>
        /// 查询全部数据
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        public async Task<List<TEntity>> QueryAsync()
        {
            return await _IbaseRepository.QueryAsync();
        }
        /// <summary>
        /// 自定义条件查询
        /// </summary>
        /// <returns></returns>
        public async Task<List<TEntity>> QueryAsync(Expression<Func<TEntity, bool>> func)
        {
            return await _IbaseRepository.QueryAsync(func);
        }
        /// <summary>
        /// 分页查询
        /// </summary>
        /// <param name="page"></param>
        /// <param name="size"></param>
        /// <param name="total"></param>
        /// <returns></returns>
        public async Task<List<TEntity>> QueryAsync(int page, int size, RefAsync<int> total)
        {
            return await _IbaseRepository.QueryAsync(page, size, total);
        }
        /// <summary>
        /// 自定义条件分页查询
        /// </summary>
        /// <param name="func"></param>
        /// <param name="page"></param>
        /// <param name="size"></param>
        /// <param name="total"></param>
        /// <returns></returns>
        public async Task<List<TEntity>> QueryAsync(Expression<Func<TEntity, bool>> func, int page, int size, RefAsync<int> total)
        {
            return await _IbaseRepository.QueryAsync(func, page, size, total);
        }
    }

IBaseService类

public interface IBaseService<TEntity> where TEntity:class,new()
    {
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<bool> CreateAsync(TEntity entity);
        /// <summary>
        /// 根据ID删除
        /// </summary>
        /// <param name="ID"></param>
        /// <returns></returns>
        Task<bool> DeleteAsync(int ID);
        /// <summary>
        /// 修改
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<bool> EditAsync(TEntity entity);
        /// <summary>
        /// 根据ID查询
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        Task<TEntity> FindAsync(int Id);
        /// <summary>
        /// 根据条件查询接口
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> func);
        /// <summary>
        /// 查询全部数据
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        Task<List<TEntity>> QueryAsync();
        /// <summary>
        /// 自定义条件查询
        /// </summary>
        /// <returns></returns>
        Task<List<TEntity>> QueryAsync(Expression<Func<TEntity, bool>> func);
        /// <summary>
        /// 分页查询
        /// </summary>
        /// <param name="func"></param>
        /// <returns></returns>
        Task<List<TEntity>> QueryAsync(int page, int size, RefAsync<int> total);
        /// <summary>
        /// 自定义条件分页查询
        /// </summary>
        /// <param name="func"></param>
        /// <param name="page"></param>
        /// <param name="size"></param>
        /// <param name="total"></param>
        /// <returns></returns>
        Task<List<TEntity>> QueryAsync(Expression<Func<TEntity, bool>> func, int page, int size, RefAsync<int> total);
    }

4、BusinessService：

BlogNewsService类

public class BlogNewsService : BaseService<Entity.BaseEntity.BlogNews>, IBlogNewsService
    {
        private readonly IBlogNewsRepository _iblogNewsRepository;
 
        public BlogNewsService(IBlogNewsRepository iblogNewsRepository)
        {
            base._IbaseRepository = iblogNewsRepository;
            _iblogNewsRepository = iblogNewsRepository;
        }
    }

IBlogNewsService类

public  interface IBlogNewsService:IBaseService<Entity.BaseEntity.BlogNews>
{
}

TypeInfoService，WriterInfoService也是一样的，修改一继承的类就行了。

ITypeInfoService，IWriterInfoService：都是继承基类的接口。