Entity Framework泛型封装-白红宇

Entity Framework泛型封装

阅读量：7077 次

发布时间：2019-06-28

本文共 6450 字，大约阅读时间需要 21 分钟。

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
     
      (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
      
       (updateUser).State = EntityState.Modified;            dbContext.SaveChanges();            //删除            User delUser = dbContext.Users.Where(item => item.ID == 2).First();            dbContext.Entry
       
        (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
     
       where T : class    {        //...    }

　新增

方法:

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

调用:

EFHelpler
     
       helper = new EFHelpler
      
       ();            BaseContext dbContext = new BaseContext();            //新增            List
       
         listUser = new List
        
         ();            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：

///         /// 实体查询        /// 
        public IEnumerable
     
       getSearchList(System.Linq.Expressions.Expression
      
       
        > where)        {            return dbContext.Set
        
         ().Where(where);        }        /// 
                 /// 实体分页查询        /// 
        /// 
                 /// 
                 /// 
                 /// 
                 /// 
                 /// 
                 public IEnumerable
         
           getSearchListByPage
          
           (Expression
           
            
             > where, Expression
             
              
               > orderBy, int pageSize, int pageIndex) { return dbContext.Set
               
                ().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
     
      (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:

///         /// 按照条件修改数据        /// 
        ///         ///         public void update(Expression
     
      
       > where, Dictionary
       
         dic)        {            IEnumerable
        
          result = dbContext.Set
         
          ().Where(where).ToList();            Type type = typeof(T);            List
          
            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
     
       dic=new Dictionary
      
       ();            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:

///         /// 实体删除        /// 
        ///         public void delete(params T[] paramList)        {            foreach (var model in paramList)            {                dbContext.Entry
     
      (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
     
       where T : class    {        BaseContext dbContext = new BaseContext();        /// 
              /// 实体新增        /// 
        /// 
              public void add(params T[] paramList)        {            foreach (var model in paramList)            {                dbContext.Entry
      
       (model).State = EntityState.Added;            }            dbContext.SaveChanges();        }        /// 
               /// 实体查询        /// 
        public IEnumerable
       
         getSearchList(System.Linq.Expressions.Expression
        
         
          > where)        {            return dbContext.Set
          
           ().Where(where); } /// 
            /// 实体分页查询 /// 
 /// 
            /// 
            /// 
            /// 
            /// 
            /// 
            public IEnumerable
           
             getSearchListByPage
            
             (Expression
             
              
               > where, Expression
               
                
                 > orderBy, int pageSize, int pageIndex) { return dbContext.Set
                 
                  ().Where(where).OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize); } /// 
                   /// 实体删除 /// 
 /// 
                   public void delete(params T[] paramList) { foreach (var model in paramList) { dbContext.Entry
                  
                   (model).State = EntityState.Deleted; } dbContext.SaveChanges(); } /// 
                    /// 按照条件修改数据 /// 
 /// 
                    /// 
                    public void update(Expression
                   
                    
                     > where, Dictionary
                     
                       dic) { IEnumerable
                      
                        result = dbContext.Set
                       
                        ().Where(where).ToList(); Type type = typeof(T); List
                        
                          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~

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