EF 5.0 帮助类

加入命名空间：

using System;using System.Data;using System.Data.Entity;using System.Data.Entity.Infrastructure;using System.Linq;

接口：

public interface IEFRepository
     
       where TEntity : class    {        bool AddEntity(TEntity entity);        bool UpdateEntity(TEntity entity);        bool UpdateEntity(IEnumerable
      
        entities);        bool DeleteEntity(int ID);        bool DeleteEntity(TEntity entity);        bool DeleteEntity(Expression
       
        
         > predicate);        bool DeleteEntity(IEnumerable
         
           entities);        IList
          
            LoadEntities(Func
           
             whereLambda); IList
            
              LoadEntities(int pageIndex = 1, int pageSize = 30, Func
             
               whereLambda = null); TEntity FindByID(int ID); }
             
            
           
          
         
        
       
      
     

具体类：

//EF5.0的写法     public class EFRepository
     
       : IEFRepository
      
        where TEntity : class    {        #region 单利模式        public static EFRepository
       
         Instance = new EFRepository
        
         ();        public EFRepository( )        {            Create();        }        #endregion        /// 
         
        /// 获取 当前使用的数据访问上下文对象        /// 
        public DbContext Context        {            get            {                return EFDbContextHelper.Context;            }        }        public bool AddEntity(TEntity entity)        {            EntityState state = Context.Entry(entity).State;            if (state == EntityState.Detached)            {                Context.Entry(entity).State = EntityState.Added;            }            Context.SaveChanges();            return true;        }        public bool UpdateEntity(TEntity entity)        {            Context.Set
         
          ().Attach(entity);            Context.Entry
          
           (entity).State = EntityState.Modified; return Context.SaveChanges() > 0; } public bool UpdateEntity(IEnumerable
           
             entities) { try { Context.Configuration.AutoDetectChangesEnabled = false; foreach (TEntity entity in entities) { UpdateEntity(entity); } return true; } finally { Context.Configuration.AutoDetectChangesEnabled = true; } } public bool DeleteEntity(int ID) { TEntity entity = FindByID(ID); return DeleteEntity(entity); } public bool DeleteEntity(TEntity entity) { Context.Set
            
             ().Attach(entity); Context.Entry
             
              (entity).State = EntityState.Deleted; return Context.SaveChanges() > 0; } public bool DeleteEntity(System.Linq.Expressions.Expression
              
               
                > predicate) { List
                
                  entities = Set().Where(predicate).ToList(); return Context.SaveChanges() > 0; } public bool DeleteEntity(IEnumerable
                 
                   entities) { try { Context.Configuration.AutoDetectChangesEnabled = false; foreach (TEntity entity in entities) { DeleteEntity(entity); } return true; } finally { Context.Configuration.AutoDetectChangesEnabled = true; } } public IList
                  
                    LoadEntities(Func
                   
                     whereLambda) { if (whereLambda != null) return Context.Set
                    
                     ().Where
                     
                      (whereLambda).AsQueryable().ToList(); else return Context.Set
                      
                       ().AsQueryable().ToList(); } public IList
                       
                         LoadEntities(int pageIndex = 1, int pageSize = 30, Func
                        
                          whereLambda = null) { int skinCount = (pageIndex - 1) * pageSize; if (whereLambda != null) return Set() .Where
                         
                          (whereLambda) .Skip(skinCount) .Take(pageSize) .ToList(); else return Set() .Skip(skinCount) .Take(pageSize) .ToList(); } public DbSet
                          
                            Set( ) { return Context.Set
                           
                            (); } public TEntity FindByID(int ID) { return Set().Find(ID); } private TEntity Create( ) { return Context.Set
                            
                             ().Create(); } }
                            
                           
                          
                         
                        
                       
                      
                     
                    
                   
                  
                 
                
               
              
             
            
           
          
         
        
       
      
     

使用：

准备实体类

/// 
     /// 实体类楼层管理 。(属性说明自动提取数据库字段的描述信息)     /// 
     [Serializable]    public class Floor     {         public int ID { get; set; }         [Category("楼层名称")]        public string f_Name { get; set; }         [Category("备注")]        public string f_Remark { get; set; }     }

使用EF帮助类调用

/// 
     /// 数据上下文 Db3983Context     /// 
     public class Db3983Context : EFDbContext     {         /// 
         /// 构造函数         /// 
         public Db3983Context()             : base("3983")         {         }         /// 
         /// 楼层管理         /// 
         public DbSet
     
       Floor { get; set; } }
     

/// 
        /// 应用程序的主入口点。        /// 
        [STAThread]        static void Main( )        {            EFDbContextHelper.Context = new Db3983Context();            Floor floor = new Floor();            floor.f_Name = "罗敏贵";            floor.f_Remark = "我这个人看上去很靠谱，长得也很高有一米八五，也很帅气，千万不要迷恋哥，哥只是传说。";            EFRepository
     
      .Instance.AddEntity(floor);        }
     

扩展：

其他ORM只要现实上面的接口就可以了，然后在配置文件制定使用哪个ORM就可以做到扩展了。

http://www.cnblogs.com/lori/archive/2012/10/19/2731801.html