Entity Framework泛型封装

Entity Framework本身的增删改查其实 已经很方便了，不过做项目的时候用的多了也就觉得有点累了，每个业务实体基本上都涉及到到了增删改查这四个基本的要素，至于封装每个公司可能都不一样，接口，设计模式都用的眼花缭乱，我闲来没事就搞个简单的封装Helper，Github上也有关于EF的扩展Libray，具体没有用过，公司的有自己的封装，自己也没怎么弄，具体地址:https://github.com/loresoft/EntityFramework.Extended.

首先来看段代码，model和context是从数据中直接生成，你可以选择自己习惯的方式:

          //新增
            User addUser = new User();
            addUser.PersonID = 3;
            addUser.UserName = "keso";
            dbContext.Entry<User>(addUser).State = EntityState.Added;
            dbContext.SaveChanges();
            //修改
            User updateUser = new User();
            dbContext.Users.Where(item => item.ID == 2).OrderBy(item => item.ID);
            updateUser.UserName = updateUser.UserName + "测试";
            dbContext.Entry<User>(updateUser).State = EntityState.Modified;
            dbContext.SaveChanges();
            //删除
            User delUser = dbContext.Users.Where(item => item.ID == 2).First();
            dbContext.Entry<User>(delUser).State = EntityState.Deleted;
            dbContext.SaveChanges();

　如果每个业务实体都这么写一遍，估计公司水准有待提高，而且开发的也该跳起来骂人，本人只是简单封装下新建一个EFHelper，实际开发会封装的更多，不过底层处理是不变的

 class EFHelpler<T> where T : class
    {
        //...
    }        

　新增

方法:

  /// <summary>
        /// 实体新增
        /// </summary>
        /// <param name="model"></param>
        public void add(params T[] paramList)
        {
            foreach (var model in paramList)
            {
                dbContext.Entry<T>(model).State = EntityState.Added;
            }
            dbContext.SaveChanges();
        }

 调用:

   EFHelpler<User> helper = new EFHelpler<User>();
            BaseContext dbContext = new BaseContext();
            //新增
            List<User> listUser = new List<User>();
            for (int i = 0; i < 2; i++)
            {
                User user = new User();
                user.PersonID = i;
                user.UserName = "FlyElehant" + i;
                listUser.Add(user);
            }
            helper.add(listUser.ToArray());
            Console.WriteLine("新增成功");

　查询

查询分了两种，一种是简单的查询，一种是分页的：

   /// <summary>
        /// 实体查询
        /// </summary>
        public IEnumerable<T> getSearchList(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            return dbContext.Set<T>().Where(where);
        }
        /// <summary>
        /// 实体分页查询
        /// </summary>
        /// <typeparam name="TKey"></typeparam>
        /// <param name="where"></param>
        /// <param name="orderBy"></param>
        /// <param name="pageSize"></param>
        /// <param name="pageIndex"></param>
        /// <returns></returns>
        public IEnumerable<T> getSearchListByPage<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> orderBy, int pageSize, int pageIndex)
        {
            return dbContext.Set<T>().Where(where).OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize);
        }

 简单调用，第二个方式除了分页之外，主要是查询的时候指定一定OrderBy的类型，也就是TKey:

     var query = helper.getSearchList(item => item.UserName.Contains("keso"));
            var queryMulti = helper.getSearchListByPage<int>(item => item.UserName.Contains("FlyElehant"), order => order.PersonID, 2, 1);
            query = queryMulti;
            foreach (User user in query)
            {
                Console.WriteLine(user.UserName);
            }

 修改

修改代码稍微读了几行，主要是用到了一下反射:

    /// <summary>
        /// 按照条件修改数据
        /// </summary>
        /// <param name="where"></param>
        /// <param name="dic"></param>
        public void update(Expression<Func<T, bool>> where, Dictionary<string, object> dic)
        {
            IEnumerable<T> result = dbContext.Set<T>().Where(where).ToList();
            Type type = typeof(T);
            List<PropertyInfo> propertyList = type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).ToList();
            //遍历结果集
            foreach (T entity in result)
            {
                foreach (PropertyInfo propertyInfo in propertyList)
                {
                    string propertyName = propertyInfo.Name;
                    if (dic.ContainsKey(propertyName))
                    {
                        //设置值
                        propertyInfo.SetValue(entity, dic[propertyName], null);
                    }
                }
            }
            dbContext.SaveChanges();
        }

 调用:

   Dictionary<string,object> dic=new Dictionary<string,object>();
            dic.Add("PersonID",2);
            dic.Add("UserName","keso");
            helper.update(item => item.UserName.Contains("keso"), dic);
            Console.WriteLine("修改成功");

删除

方法:

    /// <summary>
        /// 实体删除
        /// </summary>
        /// <param name="model"></param>
        public void delete(params T[] paramList)
        {
            foreach (var model in paramList)
            {
                dbContext.Entry<T>(model).State = EntityState.Deleted;
            }
            dbContext.SaveChanges();
        }

　　调用:

     var query = helper.getSearchList(item => item.UserName.Contains("keso"));
            helper.delete(query.ToArray());

 完整的EFHelper:

   class EFHelpler<T> where T : class
    {
        BaseContext dbContext = new BaseContext();
        /// <summary>
        /// 实体新增
        /// </summary>
        /// <param name="model"></param>
        public void add(params T[] paramList)
        {
            foreach (var model in paramList)
            {
                dbContext.Entry<T>(model).State = EntityState.Added;
            }
            dbContext.SaveChanges();
        }
        /// <summary>
        /// 实体查询
        /// </summary>
        public IEnumerable<T> getSearchList(System.Linq.Expressions.Expression<Func<T, bool>> where)
        {
            return dbContext.Set<T>().Where(where);
        }
        /// <summary>
        /// 实体分页查询
        /// </summary>
        /// <typeparam name="TKey"></typeparam>
        /// <param name="where"></param>
        /// <param name="orderBy"></param>
        /// <param name="pageSize"></param>
        /// <param name="pageIndex"></param>
        /// <returns></returns>
        public IEnumerable<T> getSearchListByPage<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> orderBy, int pageSize, int pageIndex)
        {
            return dbContext.Set<T>().Where(where).OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize);
        }

        /// <summary>
        /// 实体删除
        /// </summary>
        /// <param name="model"></param>
        public void delete(params T[] paramList)
        {
            foreach (var model in paramList)
            {
                dbContext.Entry<T>(model).State = EntityState.Deleted;
            }
            dbContext.SaveChanges();
        }
        /// <summary>
        /// 按照条件修改数据
        /// </summary>
        /// <param name="where"></param>
        /// <param name="dic"></param>
        public void update(Expression<Func<T, bool>> where, Dictionary<string, object> dic)
        {
            IEnumerable<T> result = dbContext.Set<T>().Where(where).ToList();
            Type type = typeof(T);
            List<PropertyInfo> propertyList = type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).ToList();
            //遍历结果集
            foreach (T entity in result)
            {
                foreach (PropertyInfo propertyInfo in propertyList)
                {
                    string propertyName = propertyInfo.Name;
                    if (dic.ContainsKey(propertyName))
                    {
                        //设置值
                        propertyInfo.SetValue(entity, dic[propertyName], null);
                    }
                }
            }
            dbContext.SaveChanges();
        }

    }

　个人Demo难免有表达不当或者技术失误的地方，如有不当，请多多指出，感激不尽~