public class UnitOfWork : IUnitOfWork

    {

        #region fields

        /// <summary>

        ///     服务提供器，主要用于查找 框架配置对象，以及DbContextOptionBuilder对象

        /// </summary>

        private readonly IServiceProvider _provider;

        /// <summary>

        ///     当前请求涉及的scope生命的仓储对象

        /// </summary>

        private Hashtable repositorys;

        private IDbContextTransaction _dbTransaction { get; set; }

        /// <summary>

        ///     上下文对象，UOW内部初始化上下文对象，供当前scope内的操作使用，保证同一上下文

        /// </summary>

        public DbContext DbContext => GetDbContext();

        #endregion

        #region ctor

        public UnitOfWork(IServiceProvider provider)

        {

            _provider = provider;

        }

        #endregion

        #region public

        public IRepository<TEntity, TKey> Repository<TEntity, TKey>() where TEntity : class, IEntity<TKey>

        {

            if (repositorys == null)

                repositorys = new Hashtable();

            var entityType = typeof(TEntity);

            if (!repositorys.ContainsKey(entityType.Name))

            {

                var baseType = typeof(Repository<,>);

                var repositoryInstance = Activator.CreateInstance(baseType.MakeGenericType(entityType), DbContext);

                repositorys.Add(entityType.Name, repositoryInstance);

            }

            return (IRepository<TEntity, TKey>)repositorys[entityType.Name];

        }

        public void BeginTransaction()

        {

            //DbContext.Database.UseTransaction(_dbTransaction);//如果多上下文，我们可是在其他上下文直接使用 UserTransaction使用已存在的事务

            _dbTransaction = DbContext.Database.BeginTransaction();

        }

        public int Commit()

        {

            int result = 0;

            try

            {

                result = DbContext.SaveChanges();

                if (_dbTransaction != null)

                    _dbTransaction.Commit();

            }

            catch (Exception ex)

            {

                result = -1;

                CleanChanges(DbContext);

                _dbTransaction.Rollback();

                throw new Exception($"Commit 异常：{ex.InnerException}/r{ ex.Message}");

            }

            return result;

        }

        public async Task<int> CommitAsync()

        {

            int result = 0;

            try

            {

                result = await DbContext.SaveChangesAsync();

                if (_dbTransaction != null)

                    _dbTransaction.Commit();

            }

            catch (Exception ex)

            {

                result = -1;

                CleanChanges(DbContext);

                _dbTransaction.Rollback();

                throw new Exception($"Commit 异常：{ex.InnerException}/r{ ex.Message}");

            }

            return await Task.FromResult(result);

        }

        #endregion

        #region private

        private DbContext GetDbContext()

        {

            var options = _provider.ESoftorOption();

            IDbContextOptionsBuilderCreator builderCreator = _provider.GetServices<IDbContextOptionsBuilderCreator>()

                .FirstOrDefault(d => d.DatabaseType == options.ESoftorDbOption.DatabaseType);

            if (builderCreator == null)

                throw new Exception($"无法解析数据库类型为：{options.ESoftorDbOption.DatabaseType}的{typeof(IDbContextOptionsBuilderCreator).Name}实例");

            //DbContextOptionsBuilder

            var optionsBuilder = builderCreator.Create(options.ESoftorDbOption.ConnectString, null);//TODO null可以换成缓存中获取connection对象，以便性能的提升

            if (!(ActivatorUtilities.CreateInstance(_provider, options.ESoftorDbOption.DbContextType, optionsBuilder.Options) is DbContext dbContext))

                throw new Exception($"上下文对象 “{options.ESoftorDbOption.DbContextType.AssemblyQualifiedName}” 实例化失败，请确认配置文件已正确配置。 ");

            return dbContext;

        }

        /// <summary>

        ///     操作失败，还原跟踪状态

        /// </summary>

        /// <param name="context"></param>

        private static void CleanChanges(DbContext context)

        {

            var entries = context.ChangeTracker.Entries().ToArray();

            for (int i = 0; i < entries.Length; i++)

            {

                entries[i].State = EntityState.Detached;

            }

        }

        #endregion

        #region override

        public void Dispose()

        {

            _dbTransaction.Dispose();

            DbContext.Dispose();

            GC.SuppressFinalize(this);

        }

        #endregion

    }