public virtual Task<int> SaveChangesAsync();

/// <summary>
        /// 異步提交到數據庫
        /// </summary>
        protected async Task SaveChangesAsync()
        {
            try
            {
                await Db.SaveChangesAsync();
            }
            catch (System.Data.Entity.Validation.DbEntityValidationException dbEx)//捕(bu)獲實體(ti)驗(yan)證(zheng)異(yi)常
            {
                var sb = new StringBuilder();
                dbEx.EntityValidationErrors.First().ValidationErrors.ToList().ForEach(i =>
                {
                    sb.AppendFormat("屬性為：{0}，信息為：{1}\n\r", i.PropertyName, i.ErrorMessage);
                });
                if (Logger == null)
                    throw new Exception(sb.ToString());
                Logger(sb.ToString() + "處(chu)理時(shi)間：" + DateTime.Now);

            }
            catch (OptimisticConcurrencyException)//并發沖(chong)突(tu)異常(chang)
            {

            }
            catch (Exception ex)//捕獲所有(you)異常
            {
                if (Logger == null)//如果沒有定義日志(zhi)功能，就把異常拋出(chu)來吧
                    throw new Exception(ex.Message);
                Logger(ex.Message + "處理時間：" + DateTime.Now);
            }

#region 異步操作－顯示實現的接口，只能為接口實例進行調用
        #region IExtensionRepositoryAsync<TEntity> 成員

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.Insert(IEnumerable<TEntity> item)
        {
            item.ToList().ForEach(i =>
            {
                Db.Entry<TEntity>(i);
                Db.Set<TEntity>().Add(i);
            });
            await this.SaveChangesAsync();
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.Update(IEnumerable<TEntity> item)
        {
            item.ToList().ForEach(i =>
            {
                Db.Set<TEntity>().Attach(i);
                Db.Entry(i).State = EntityState.Modified;
            });
            try
            {
                await this.SaveChangesAsync();
            }
            catch (OptimisticConcurrencyException)//并(bing)發沖突(tu)異(yi)常(chang)
            {
            }
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.Delete(IEnumerable<TEntity> item)
        {
            item.ToList().ForEach(i =>
            {
                Db.Set<TEntity>().Attach(i);
                Db.Set<TEntity>().Remove(i);
            });
            await this.SaveChangesAsync();
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.BulkInsert(IEnumerable<TEntity> item, bool isRemoveIdentity)
        {
            await Task.Run(() =>
            {
                this.BulkInsert(item, isRemoveIdentity);
            });
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.BulkInsert(IEnumerable<TEntity> item)
        {
            await Task.Run(() =>
            {
                this.BulkInsert(item);
            });
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.BulkUpdate(IEnumerable<TEntity> item, params string[] fieldParams)
        {
            await Task.Run(() =>
            {
                this.BulkUpdate(item);
            });
        }

        async System.Threading.Tasks.Task IExtensionRepositoryAsync<TEntity>.BulkDelete(IEnumerable<TEntity> item)
        {
            await Task.Run(() =>
            {
                this.BulkDelete(item);
            });
        }

        #endregion

        #region IRepositoryAsync<TEntity> 成員


        async System.Threading.Tasks.Task IRepositoryAsync<TEntity>.Insert(TEntity item)
        {
            OnBeforeSaved(new SavedEventArgs(item, SaveAction.Insert));
            Db.Entry<TEntity>(item);
            Db.Set<TEntity>().Add(item);
            await this.SaveChangesAsync();
            OnAfterSaved(new SavedEventArgs(item, SaveAction.Insert));
        }

        async System.Threading.Tasks.Task IRepositoryAsync<TEntity>.Delete(TEntity item)
        {
            OnBeforeSaved(new SavedEventArgs(item, SaveAction.Delete));
            Db.Set<TEntity>().Attach(item);
            Db.Set<TEntity>().Remove(item);
            await this.SaveChangesAsync();
            OnAfterSaved(new SavedEventArgs(item, SaveAction.Delete));
        }

        async System.Threading.Tasks.Task IRepositoryAsync<TEntity>.Update(TEntity item)
        {
            OnBeforeSaved(new SavedEventArgs(item, SaveAction.Update));
            Db.Set<TEntity>().Attach(item);
            Db.Entry(item).State = EntityState.Modified;
            try
            {
                await this.SaveChangesAsync();
            }
            catch (OptimisticConcurrencyException)//并發沖突異常
            {

            }

            OnAfterSaved(new SavedEventArgs(item, SaveAction.Update));
        }

        #endregion
        #endregion