【无私分享：ASP.NET CORE 项目实战（第五章）】Repository仓储 UnitofWork

 

目录索引　

 

【无私分享：ASP.NET CORE 项目实战】目录索引

 

简介

 

　　本章我们来创建仓储类Repository 并且引入 UnitOfWork

 

 

我对UnitOfWork的一些理解

 

　　 UnitOfWork 工作单元，对于这个的解释和实例，网上很多很多大神之作，我在这就不班门弄斧了，只是浅谈 一下个人理解，不一定对，希望大家指正：

　　UnitOfWork 看了很多，个人理解就是 统一事务，在很多操作中我们可能是进行多项操作的，比如 同时保存两个表的数据，如果我们先保存一个表（SaveChanges()之后），再保存另一个表（SaveChanges()）其实是两个不同的事务，通俗的讲，我们对数据库提交了两次数据。而UnitOfWork 就是 把本次操作（分别保存两张表）放在统一事务中，所有的CRUD完成后，统一提交数据，即保证数据的一致性，又减少了提交次数，提高性能。

　　举个例子，我们之前的Repository的保存操作：

　　Repository:

　　public virtual bool Save(T entity)
　　{
　　　　_Context.Add(entity);
　　　　return _Context.SaveChanges() > 0;
　　}

 

　　Controller: 

　　public ActionResult Save()

　　{

　　　　var Users=new Users(){Id=1,UserName="张三"};

　　　　var Logs=new Logs(){log="注册了用户张三"};

　　　　_UserService.Save(Users);

　　　　_LogService.Save(Logs);

　　}

因为本身EF就是带事务的，但是_Context.SaveChanges()之后，事务就结束了，也提交了数据。所以，上面的例子 应该是开启了两次事务，提交了两次数据（一次是Users 一次是 Logs）

这显然是不合理的，首先不说提交两次数据性能的问题，如果用户注册失败，那么日志也不应该添加，应该回滚。但是，显然，上面没有这么做。

所以有了UnitOfWork。

使用UnitOfWork之后，代码应该是这样的：

 

　　UnitOfWork:

　　public bool Commit()
　　{
　　　　return _Context.SaveChanges() > 0; 
　　}

 

　　Repository:

　　public virtual bool Save(T entity)
　　{
　　　　_Context.Add(entity);
　　}

 

　　Controller: 

　　public ActionResult Save()

　　{

　　　　var Users=new Users(){Id=1,UserName="张三"};

　　　　var Logs=new Logs(){log="注册了用户张三"};

　　　　_UserService.Save(Users);

　　　　_LogService.Save(Logs);

　　　　_UnitOfWork.Commit();

　　}

　　

 

UnitOfWork接口和实现类

 我们在wkmvc.Core类库下，新建一个接口 IUnitOfWork：

namespace wkmvc.Core
{
    /// <summary>
    /// Describe：工作单元接口
    /// Author：yuangang
    /// Date：2016/07/16
    /// Blogs:http://www.cnblogs.com/yuangang
    /// </summary>
    public interface IUnitOfWork
    {
        bool Commit();
    }
}

  

　　IUnitOfWork 实现类 UnitOfWork：

using System;
using wkmvc.Data;

namespace wkmvc.Core
{
    /// <summary>
    /// Describe：工作单元实现类
    /// Author：yuangang
    /// Date：2016/07/16
    /// Blogs:http://www.cnblogs.com/yuangang
    /// </summary>
    public class UnitOfWork : IUnitOfWork, IDisposable
    {
        #region 数据上下文

        /// <summary>
        /// 数据上下文
        /// </summary>
        private ApplicationDbContext _Context;
        public UnitOfWork(ApplicationDbContext Context)
        {
            _Context = Context;
        }

        #endregion

        public bool Commit()
        {
            return _Context.SaveChanges() > 0;
        }

        public void Dispose()
        {
            if(_Context!=null)
            {
                _Context.Dispose();
            }
            GC.SuppressFinalize(this);
        }
    }
}

 

 

　　 这样，UnitOfWork 就完成了。下面我们来添加仓储：

 

仓储 IRepository、Repository

新建接口 IRepository 添加基本的操作方法：

 

using System;
using System.Linq.Expressions;

namespace wkmvc.Core
{
    /// <summary>
    /// Describe：仓储接口
    /// Author：yuangang
    /// Date：2016/07/16
    /// Blogs:http://www.cnblogs.com/yuangang
    /// </summary>
    /// <typeparam name="T">实体模型</typeparam>
    public interface IRepository<T> where T : class
    {
        #region 单模型 CRUD 操作

        /// <summary>
        /// 增加一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Save(T entity, bool IsCommit = true);

        /// <summary>
        /// 更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Update(T entity, bool IsCommit = true);

        /// <summary>
        /// 增加或更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true);

        /// <summary>
        /// 通过Lamda表达式获取实体
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        T Get(Expression<Func<T, bool>> predicate);

        /// <summary>
        /// 删除一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Delete(T entity, bool IsCommit = true);

        #endregion
    }
}

 

 

　　 实现类 Repository :

 

 

 

using Microsoft.EntityFrameworkCore;
using System;
using System.Linq;
using System.Linq.Expressions;
using wkmvc.Data;

namespace wkmvc.Core
{
    /// <summary>
    /// Describe：仓储实现类
    /// Author：yuangang
    /// Date：2016/07/16
    /// Blogs:http://www.cnblogs.com/yuangang
    /// </summary>
    /// <typeparam name="T">实体模型</typeparam>
    public abstract class Repository<T> : IRepository<T> where T : class
    {
        #region 数据上下文

        /// <summary>
        /// 数据上下文
        /// </summary>
        private ApplicationDbContext _Context;

        /// <summary>
        /// 工作单元
        /// </summary>
        UnitOfWork _UnitOfWork;

        public Repository(ApplicationDbContext Context)
        {
            _Context = Context;
            _UnitOfWork = new UnitOfWork(_Context);
        }


        #endregion

        #region 单模型 CRUD 操作

        /// <summary>
        /// 增加一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Save(T entity,bool IsCommit=true)
        {
            _Context.Add(entity);
            if (IsCommit)
                return _UnitOfWork.Commit();
            else
                return false;
        }

        /// <summary>
        /// 更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Update(T entity, bool IsCommit = true)
        {
            _Context.Attach(entity);
            _Context.Entry(entity).State = EntityState.Modified;
            if (IsCommit)
                return _UnitOfWork.Commit();
            else
                return false;
        }

        /// <summary>
        /// 增加或更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true)
        {
            return IsSave ? Save(entity, IsCommit) : Update(entity, IsCommit);
        }

        /// <summary>
        /// 通过Lamda表达式获取实体
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        public virtual T Get(Expression<Func<T, bool>> predicate)
        {
            return _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate);
        }


        /// <summary>
        /// 删除一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Delete(T entity, bool IsCommit = true)
        {
            if (entity == null) return false;
            _Context.Remove(entity);

            if (IsCommit)
                return _UnitOfWork.Commit();
            else
                return false;
        }

        #endregion


    }
}

 

我们都添加了一个  bool IsCommit = true 参数，是为了方便，如果仅仅是进行一项操作，那就没必要使用 UnitOfWork 统一 直接 SaveChanages() 就行了

 

 

 

我们来看下使用： 

　　//第一种
　　public bool TestOne()
　　{
　　　　var users = new SYS_USER() { UserName="张三",Account="zhangsan",Password="123456" };

　　　　return _UserService.Save(users);
　　}

　　//第二种
　　public bool TestTwo()
　　{
　　　　var users1 = new SYS_USER() { UserName = "张三", Account = "zhangsan", Password = "123456" };
　　　　var users2 = new SYS_USER() { UserName = "李四", Account = "lisi", Password = "456789" };
　　　　var users3 = new SYS_USER() { UserName = "王五", Account = "wangwu", Password = "321654" };

　　　　_UserService.Save(users1);
　　　　_UserService.Save(users2);
　　　　_UserService.Save(users3);

　　　　return _UnitOfWork.Commit();
　　}

 

本篇主要是介绍用法，具体的解释清大家参考大神们的讲解，如有不对的地方希望指正。具体的实现代码，我们后面一起一点一点写。

 

 

给大家贴一下个人实现的仓储 IRepository、Repository代码：

 

IRepository：

    public interface IRepository<T> where T : class
    {
        #region 单模型 CRUD 操作

        /// <summary>
        /// 增加一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Save(T entity, bool IsCommit = true);
        /// <summary>
        /// 增加一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> SaveAsync(T entity, bool IsCommit = true);

        /// <summary>
        /// 更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Update(T entity, bool IsCommit = true);
        /// <summary>
        /// 更新一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> UpdateAsync(T entity, bool IsCommit = true);

        /// <summary>
        /// 增加或更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true);
        /// <summary>
        /// 增加或更新一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> SaveOrUpdateAsync(T entity, bool IsSave, bool IsCommit = true);

        /// <summary>
        /// 通过Lamda表达式获取实体
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        T Get(Expression<Func<T, bool>> predicate);
        /// <summary>
        /// 通过Lamda表达式获取实体（异步方式）
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        Task<T> GetAsync(Expression<Func<T, bool>> predicate);

        /// <summary>
        /// 删除一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool Delete(T entity, bool IsCommit = true);
        /// <summary>
        /// 删除一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> DeleteAsync(T entity, bool IsCommit = true);

        #endregion

        #region 多模型 操作

        /// <summary>
        /// 增加多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool SaveList(List<T> T1, bool IsCommit = true);
        /// <summary>
        /// 增加多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> SaveListAsync(List<T> T1, bool IsCommit = true);

        /// <summary>
        /// 增加多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool SaveList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
        /// <summary>
        /// 增加多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> SaveListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;

        /// <summary>
        /// 更新多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool UpdateList(List<T> T1, bool IsCommit = true);
        /// <summary>
        /// 更新多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> UpdateListAsync(List<T> T1, bool IsCommit = true);

        /// <summary>
        /// 更新多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool UpdateList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
        /// <summary>
        /// 更新多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> UpdateListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;

        /// <summary>
        /// 删除多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool DeleteList(List<T> T1, bool IsCommit = true);
        /// <summary>
        /// 删除多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> DeleteListAsync(List<T> T1, bool IsCommit = true);

        /// <summary>
        /// 删除多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        bool DeleteList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
        /// <summary>
        /// 删除多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        Task<bool> DeleteListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;

        /// <summary>
        /// 通过Lamda表达式，删除一条或多条记录
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="IsCommit"></param>
        /// <returns></returns>
        bool Delete(Expression<Func<T, bool>> predicate, bool IsCommit = true);
        /// <summary>
        /// 通过Lamda表达式，删除一条或多条记录（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="IsCommit"></param>
        /// <returns></returns>
        Task<bool> DeleteAsync(Expression<Func<T, bool>> predicate, bool IsCommit = true);

        #endregion

        #region 获取多条数据操作

        /// <summary>
        /// 返回IQueryable集合，延时加载数据
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        IQueryable<T> LoadAll(Expression<Func<T, bool>> predicate);
        /// <summary>
        /// 返回IQueryable集合，延时加载数据（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        Task<IQueryable<T>> LoadAllAsync(Expression<Func<T, bool>> predicate);

        // <summary>
        /// 返回List<T>集合,不采用延时加载
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        List<T> LoadListAll(Expression<Func<T, bool>> predicate);
        // <summary>
        /// 返回List<T>集合,不采用延时加载（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        Task<List<T>> LoadListAllAsync(Expression<Func<T, bool>> predicate);

        /// <summary>
        /// T-Sql方式：返回IQueryable<T>集合
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        IQueryable<T> LoadAllBySql(string sql, params DbParameter[] para);
        /// <summary>
        /// T-Sql方式：返回IQueryable<T>集合（异步方式）
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        Task<IQueryable<T>> LoadAllBySqlAsync(string sql, params DbParameter[] para);

        /// <summary>
        /// T-Sql方式：返回List<T>集合
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        List<T> LoadListAllBySql(string sql, params DbParameter[] para);
        /// <summary>
        /// T-Sql方式：返回List<T>集合（异步方式）
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        Task<List<T>> LoadListAllBySqlAsync(string sql, params DbParameter[] para);

        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>实体集合</returns>
        List<TResult> QueryEntity<TEntity, TOrderBy, TResult>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby,Expression<Func<TEntity, TResult>> selector,bool IsAsc)
            where TEntity : class
            where TResult : class;
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>实体集合</returns>
        Task<List<TResult>> QueryEntityAsync<TEntity, TOrderBy, TResult>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Expression<Func<TEntity, TResult>> selector, bool IsAsc)
            where TEntity : class
            where TResult : class;

        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>自定义实体集合</returns>
        List<object> QueryObject<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby,Func<IQueryable<TEntity>,List<object>> selector,bool IsAsc)
            where TEntity : class;
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>自定义实体集合</returns>
        Task<List<object>> QueryObjectAsync<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>, List<object>> selector, bool IsAsc)
            where TEntity : class;

        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>动态类</returns>
        dynamic QueryDynamic<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>,List<object>> selector,bool IsAsc)
            where TEntity : class;
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>动态类</returns>
        Task<dynamic> QueryDynamicAsync<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>, List<object>> selector, bool IsAsc)
            where TEntity : class;

        #endregion

        #region 验证是否存在

        /// <summary>
        /// 验证当前条件是否存在相同项
        /// </summary>
        bool IsExist(Expression<Func<T, bool>> predicate);
        /// <summary>
        /// 验证当前条件是否存在相同项（异步方式）
        /// </summary>
        Task<bool> IsExistAsync(Expression<Func<T, bool>> predicate);

        /// <summary>
        /// 根据SQL验证实体对象是否存在
        /// </summary>
        bool IsExist(string sql, params DbParameter[] para);
        /// <summary>
        /// 根据SQL验证实体对象是否存在（异步方式）
        /// </summary>
        Task<bool> IsExistAsync(string sql, params DbParameter[] para);

        #endregion
    }

 

Repository：

  public abstract class Repository<T> : IRepository<T> where T : class
    {
        #region 数据上下文

        /// <summary>
        /// 数据上下文
        /// </summary>
        private ApplicationDbContext _Context;       

        public Repository(ApplicationDbContext Context)
        {
            _Context = Context;
        }

        #endregion

        #region 单模型 CRUD 操作

        /// <summary>
        /// 增加一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Save(T entity,bool IsCommit=true)
        {
            _Context.Set<T>().Add(entity);
            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 增加一条记录(异步方式)
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> SaveAsync(T entity, bool IsCommit = true)
        {
            _Context.Set<T>().Add(entity);
            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false); 
        }

        /// <summary>
        /// 更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Update(T entity, bool IsCommit = true)
        {
            _Context.Set<T>().Attach(entity);
            _Context.Entry<T>(entity).State = EntityState.Modified;
            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 更新一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> UpdateAsync(T entity, bool IsCommit = true)
        {
            _Context.Set<T>().Attach(entity);
            _Context.Entry<T>(entity).State = EntityState.Modified;
            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 增加或更新一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true)
        {
            return IsSave ? Save(entity, IsCommit) : Update(entity, IsCommit);
        }
        /// <summary>
        /// 增加或更新一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsSave">是否增加</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> SaveOrUpdateAsync(T entity, bool IsSave, bool IsCommit = true)
        {
            return IsSave ? await SaveAsync(entity, IsCommit) : await UpdateAsync(entity, IsCommit);
        }

        /// <summary>
        /// 通过Lamda表达式获取实体
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        public virtual T Get(Expression<Func<T, bool>> predicate)
        {
            return _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate);
        }
        /// <summary>
        /// 通过Lamda表达式获取实体（异步方式）
        /// </summary>
        /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
        /// <returns></returns>
        public virtual async Task<T> GetAsync(Expression<Func<T, bool>> predicate)
        {
            return await Task.Run(()=> _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate));
        }

        /// <summary>
        /// 删除一条记录
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool Delete(T entity, bool IsCommit = true)
        {
            if (entity == null) return false;
            _Context.Set<T>().Attach(entity);
            _Context.Set<T>().Remove(entity);

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 删除一条记录（异步方式）
        /// </summary>
        /// <param name="entity">实体模型</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> DeleteAsync(T entity, bool IsCommit = true)
        {
            if (entity == null) return await Task.Run(() => false);
            _Context.Set<T>().Attach(entity);
            _Context.Set<T>().Remove(entity);
            if (IsCommit)
                return  await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false); ;
        }

        #endregion

        #region 多模型 操作

        /// <summary>
        /// 增加多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool SaveList(List<T> T1, bool IsCommit = true) 
        {
            if (T1 == null || T1.Count == 0) return false;

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Add(item);
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 增加多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> SaveListAsync(List<T> T1, bool IsCommit = true)
        {
            if (T1 == null || T1.Count == 0) return await Task.Run(() => false);

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Add(item);
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 增加多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool SaveList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return false;
            var tmp = _Context.ChangeTracker.Entries<T>().ToList();
            foreach (var x in tmp)
            {
                var properties = typeof(T).GetTypeInfo().GetProperties();
                foreach (var y in properties)
                {
                    var entry = x.Property(y.Name);
                    entry.CurrentValue = entry.OriginalValue;
                    entry.IsModified = false;
                    y.SetValue(x.Entity, entry.OriginalValue);
                }
                x.State = EntityState.Unchanged;
            }
            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Add(item);
            });
            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 增加多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> SaveListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return await Task.Run(() => false);
            var tmp = _Context.ChangeTracker.Entries<T>().ToList();
            foreach (var x in tmp)
            {
                var properties = typeof(T).GetTypeInfo().GetProperties();
                foreach (var y in properties)
                {
                    var entry = x.Property(y.Name);
                    entry.CurrentValue = entry.OriginalValue;
                    entry.IsModified = false;
                    y.SetValue(x.Entity, entry.OriginalValue);
                }
                x.State = EntityState.Unchanged;
            }
            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Add(item);
            });
            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 更新多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool UpdateList(List<T> T1, bool IsCommit = true)
        {
            if (T1 == null || T1.Count == 0) return false;

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Attach(item);
                _Context.Entry<T>(item).State = EntityState.Modified;
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 更新多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> UpdateListAsync(List<T> T1, bool IsCommit = true)
        {
            if (T1 == null || T1.Count == 0) return await Task.Run(() => false);

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Attach(item);
                _Context.Entry<T>(item).State = EntityState.Modified;
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 更新多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool UpdateList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return false;

            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Attach(item);
                _Context.Entry<T1>(item).State = EntityState.Modified;
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 更新多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> UpdateListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return await Task.Run(() => false);

            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Attach(item);
                _Context.Entry<T1>(item).State = EntityState.Modified;
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 删除多条记录，同一模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool DeleteList(List<T> T1, bool IsCommit = true)
        {
            if (T1 == null || T1.Count == 0) return false;

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Attach(item);
                _Context.Set<T>().Remove(item);
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 删除多条记录，同一模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> DeleteListAsync(List<T> T1, bool IsCommit = true)
        {
            if (T1 == null || T1.Count == 0) return await Task.Run(() => false);

            T1.ToList().ForEach(item =>
            {
                _Context.Set<T>().Attach(item);
                _Context.Set<T>().Remove(item);
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 删除多条记录，独立模型
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual bool DeleteList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return false;

            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Attach(item);
                _Context.Set<T1>().Remove(item);
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 删除多条记录，独立模型（异步方式）
        /// </summary>
        /// <param name="T1">实体模型集合</param>
        /// <param name="IsCommit">是否提交（默认提交）</param>
        /// <returns></returns>
        public virtual async Task<bool> DeleteListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
        {
            if (T == null || T.Count == 0) return await Task.Run(() => false);

            T.ToList().ForEach(item =>
            {
                _Context.Set<T1>().Attach(item);
                _Context.Set<T1>().Remove(item);
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        /// <summary>
        /// 通过Lamda表达式，删除一条或多条记录
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="IsCommit"></param>
        /// <returns></returns>
        public virtual bool Delete(Expression<Func<T, bool>> predicate, bool IsCommit = true)
        {
            IQueryable<T> entry = (predicate == null) ? _Context.Set<T>().AsQueryable() : _Context.Set<T>().Where(predicate);
            List<T> list = entry.ToList();

            if (list != null && list.Count == 0) return false;
            list.ForEach(item => {
                _Context.Set<T>().Attach(item);
                _Context.Set<T>().Remove(item);
            });

            if (IsCommit)
                return _Context.SaveChanges() > 0;
            else
                return false;
        }
        /// <summary>
        /// 通过Lamda表达式，删除一条或多条记录（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="IsCommit"></param>
        /// <returns></returns>
        public virtual async Task<bool> DeleteAsync(Expression<Func<T, bool>> predicate, bool IsCommit = true)
        {
            IQueryable<T> entry = (predicate == null) ? _Context.Set<T>().AsQueryable() : _Context.Set<T>().Where(predicate);
            List<T> list = entry.ToList();

            if (list != null && list.Count == 0) return await Task.Run(() => false);
            list.ForEach(item => {
                _Context.Set<T>().Attach(item);
                _Context.Set<T>().Remove(item);
            });

            if (IsCommit)
                return await Task.Run(() => _Context.SaveChanges() > 0);
            else
                return await Task.Run(() => false);
        }

        #endregion

        #region 获取多条数据操作

        /// <summary>
        /// Lamda返回IQueryable集合，延时加载数据
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public virtual IQueryable<T> LoadAll(Expression<Func<T, bool>> predicate)
        {
            return predicate != null ? _Context.Set<T>().Where(predicate).AsNoTracking<T>() : _Context.Set<T>().AsQueryable<T>().AsNoTracking<T>();            
        }
        /// <summary>
        /// 返回IQueryable集合，延时加载数据（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public virtual async Task<IQueryable<T>> LoadAllAsync(Expression<Func<T, bool>> predicate)
        {
            return predicate != null ? await Task.Run(()=> _Context.Set<T>().Where(predicate).AsNoTracking<T>()) : await Task.Run(() => _Context.Set<T>().AsQueryable<T>().AsNoTracking<T>());
        }

        /// <summary>
        /// 返回List<T>集合,不采用延时加载
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public virtual List<T> LoadListAll(Expression<Func<T, bool>> predicate)
        {
            return predicate != null ? _Context.Set<T>().Where(predicate).AsNoTracking().ToList() : _Context.Set<T>().AsQueryable<T>().AsNoTracking().ToList();
        }
        // <summary>
        /// 返回List<T>集合,不采用延时加载（异步方式）
        /// </summary>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public virtual async Task<List<T>> LoadListAllAsync(Expression<Func<T, bool>> predicate)
        {
            return predicate != null ? await Task.Run(() => _Context.Set<T>().Where(predicate).AsNoTracking().ToList()) : await Task.Run(() => _Context.Set<T>().AsQueryable<T>().AsNoTracking().ToList());
        }

        /// <summary>
        /// T-Sql方式：返回IQueryable<T>集合
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        public virtual IQueryable<T> LoadAllBySql(string sql, params DbParameter[] para)
        {
            return _Context.Set<T>().FromSql(sql, para);
        }
        /// <summary>
        /// T-Sql方式：返回IQueryable<T>集合（异步方式）
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        public virtual async Task<IQueryable<T>> LoadAllBySqlAsync(string sql, params DbParameter[] para)
        {
            return await Task.Run(() => _Context.Set<T>().FromSql(sql, para));
        }


        /// <summary>
        /// T-Sql方式：返回List<T>集合
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        public virtual List<T> LoadListAllBySql(string sql, params DbParameter[] para)
        {
            return _Context.Set<T>().FromSql(sql, para).Cast<T>().ToList();
        }
        /// <summary>
        /// T-Sql方式：返回List<T>集合（异步方式）
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="para">Parameters参数</param>
        /// <returns></returns>
        public virtual async Task<List<T>> LoadListAllBySqlAsync(string sql, params DbParameter[] para)
        {
            return await Task.Run(()=> _Context.Set<T>().FromSql(sql, para).Cast<T>().ToList());
        }

        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>实体集合</returns>
        public virtual List<TResult> QueryEntity<TEntity, TOrderBy, TResult>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Expression<Func<TEntity, TResult>> selector,
            bool IsAsc)
            where TEntity : class
            where TResult : class
        {
            IQueryable<TEntity> query = _Context.Set<TEntity>();
            if (where != null)
            {
                query = query.Where(where);
            }

            if (orderby != null)
            {
                query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
            }
            if (selector == null)
            {
                return query.Cast<TResult>().AsNoTracking().ToList();
            }
            return query.Select(selector).AsNoTracking().ToList();
        }
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>实体集合</returns>
        public virtual async Task<List<TResult>> QueryEntityAsync<TEntity, TOrderBy, TResult>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Expression<Func<TEntity, TResult>> selector,
            bool IsAsc)
            where TEntity : class
            where TResult : class
        {
            IQueryable<TEntity> query = _Context.Set<TEntity>();
            if (where != null)
            {
                query = query.Where(where);
            }

            if (orderby != null)
            {
                query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
            }
            if (selector == null)
            {
                return await Task.Run(() => query.Cast<TResult>().AsNoTracking().ToList());
            }
            return await Task.Run(() => query.Select(selector).AsNoTracking().ToList());
        }

        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>自定义实体集合</returns>
        public virtual List<object> QueryObject<TEntity, TOrderBy>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Func<IQueryable<TEntity>,
            List<object>> selector,
            bool IsAsc)
            where TEntity : class
        {
            IQueryable<TEntity> query = _Context.Set<TEntity>();
            if (where != null)
            {
                query = query.Where(where);
            }

            if (orderby != null)
            {
                query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
            }
            if (selector == null)
            {
                return query.AsNoTracking().ToList<object>();
            }
            return selector(query);
        }
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>自定义实体集合</returns>
        public virtual async Task<List<object>> QueryObjectAsync<TEntity, TOrderBy>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Func<IQueryable<TEntity>,
            List<object>> selector,
            bool IsAsc)
            where TEntity : class
        {
            IQueryable<TEntity> query = _Context.Set<TEntity>();
            if (where != null)
            {
                query = query.Where(where);
            }

            if (orderby != null)
            {
                query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
            }
            if (selector == null)
            {
                return await Task.Run(() => query.AsNoTracking().ToList<object>());
            }
            return await Task.Run(() => selector(query));
        }


        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>动态类</returns>
        public virtual dynamic QueryDynamic<TEntity, TOrderBy>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Func<IQueryable<TEntity>,
            List<object>> selector,
            bool IsAsc)
            where TEntity : class
        {
            List<object> list = QueryObject<TEntity, TOrderBy>
                 (where, orderby, selector, IsAsc);
            return Common.JsonHelper.JsonConvert.JsonClass(list);
        }
        /// <summary>
        /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合（异步方式）
        /// </summary>
        /// <typeparam name="TEntity">实体对象</typeparam>
        /// <typeparam name="TOrderBy">排序字段类型</typeparam>
        /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
        /// <param name="orderby">排序字段</param>
        /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
        /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
        /// <returns>动态类</returns>
        public virtual async Task<dynamic> QueryDynamicAsync<TEntity, TOrderBy>
            (Expression<Func<TEntity, bool>> where,
            Expression<Func<TEntity, TOrderBy>> orderby,
            Func<IQueryable<TEntity>,
            List<object>> selector,
            bool IsAsc)
            where TEntity : class
        {
            List<object> list = QueryObject<TEntity, TOrderBy>
                 (where, orderby, selector, IsAsc);
            return await Task.Run(() => Common.JsonHelper.JsonConvert.JsonClass(list)) ;
        }

        #endregion

        #region 验证是否存在

        /// <summary>
        /// 验证当前条件是否存在相同项
        /// </summary>
        public virtual bool IsExist(Expression<Func<T, bool>> predicate)
        {
            var entry = _Context.Set<T>().Where(predicate);
            return (entry.Any());
        }
        /// <summary>
        /// 验证当前条件是否存在相同项（异步方式）
        /// </summary>
        public virtual async Task<bool> IsExistAsync(Expression<Func<T, bool>> predicate)
        {
            var entry = _Context.Set<T>().Where(predicate);
            return await Task.Run(() => entry.Any());
        }

        /// <summary>
        /// 根据SQL验证实体对象是否存在
        /// </summary>
        public virtual bool IsExist(string sql, params DbParameter[] para)
        {
            return _Context.Database.ExecuteSqlCommand(sql, para) > 0;
        }
        /// <summary>
        /// 根据SQL验证实体对象是否存在（异步方式）
        /// </summary>
        public virtual async Task<bool> IsExistAsync(string sql, params DbParameter[] para)
        {
            return await Task.Run(() => _Context.Database.ExecuteSqlCommand(sql, para) > 0);
        }

        #endregion

    }

 

 

 

 

 

希望跟大家一起学习Asp.net Core 

刚开始接触，水平有限，很多东西都是自己的理解和翻阅网上大神的资料，如果有不对的地方和不理解的地方，希望大家指正！

虽然Asp.net Core 现在很火热，但是网上的很多资料都是前篇一律的复制，所以有很多问题我也暂时没有解决，希望大家能共同帮助一下！

 

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