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<TEntity> where TEntity : class
{
bool AddEntity(TEntity entity);
bool UpdateEntity(TEntity entity);
bool UpdateEntity(IEnumerable<TEntity> entities);
bool DeleteEntity(int ID);
bool DeleteEntity(TEntity entity);
bool DeleteEntity(Expression<Func<TEntity, bool>> predicate);
bool DeleteEntity(IEnumerable<TEntity> entities);
IList<TEntity> LoadEntities(Func<TEntity, bool> whereLambda);
IList<TEntity> LoadEntities(int pageIndex = 1, int pageSize = 30, Func<TEntity, bool> whereLambda = null);
TEntity FindByID(int ID);
}
具体类：
//EF5.0的写法
public class EFRepository<TEntity> : IEFRepository<TEntity> where TEntity : class
{
#region 单利模式
public static EFRepository<TEntity> Instance = new EFRepository<TEntity>();
public EFRepository( )
{
Create();
}
#endregion
/// <summary>
/// 获取 当前使用的数据访问上下文对象
/// </summary>
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<TEntity>().Attach(entity);
Context.Entry<TEntity>(entity).State = EntityState.Modified;
return Context.SaveChanges() > 0;
}
public bool UpdateEntity(IEnumerable<TEntity> 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<TEntity>().Attach(entity);
Context.Entry<TEntity>(entity).State = EntityState.Deleted;
return Context.SaveChanges() > 0;
}
public bool DeleteEntity(System.Linq.Expressions.Expression<Func<TEntity, bool>> predicate)
{
List<TEntity> entities = Set().Where(predicate).ToList();
return Context.SaveChanges() > 0;
}
public bool DeleteEntity(IEnumerable<TEntity> entities)
{
try
{
Context.Configuration.AutoDetectChangesEnabled = false;
foreach (TEntity entity in entities)
{
DeleteEntity(entity);
}
return true;
}
finally
{
Context.Configuration.AutoDetectChangesEnabled = true;
}
}
public IList<TEntity> LoadEntities(Func<TEntity, bool> whereLambda)
{
if (whereLambda != null)
return Context.Set<TEntity>().Where<TEntity>(whereLambda).AsQueryable().ToList();
else
return Context.Set<TEntity>().AsQueryable().ToList();
}
public IList<TEntity> LoadEntities(int pageIndex = 1, int pageSize = 30, Func<TEntity, bool> whereLambda = null)
{
int skinCount = (pageIndex - 1) * pageSize;
if (whereLambda != null)
return Set()
.Where<TEntity>(whereLambda)
.Skip(skinCount)
.Take(pageSize)
.ToList();
else
return Set()
.Skip(skinCount)
.Take(pageSize)
.ToList();
}
public DbSet<TEntity> Set( )
{
return Context.Set<TEntity>();
}
public TEntity FindByID(int ID)
{
return Set().Find(ID);
}
private TEntity Create( )
{
return Context.Set<TEntity>().Create();
}
}
使用：
准备实体类
/// <summary>
/// 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)
/// </summary>
[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
/// <summary>
/// 数据上下文 Db3983Context
/// </summary>
public class Db3983Context : EFDbContext
{
/// <summary>
/// 构造函数
/// </summary>
public Db3983Context()
: base("3983")
{
}
/// <summary>
/// 楼层管理
/// </summary>
public DbSet<Floor> Floor { get; set; }
}
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[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<Floor>.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作者：罗敏贵 邮箱：minguiluo@gmail.com QQ群：34178394 建群 主要是寻找志同道合的人士一起学习和讨论自己的所学所思 出处：http://luomingui.cnblogs.com/ 说明：专注于微软平台项目架构、熟悉设计模式、架构设计、敏捷个人和项目管理。现主要从事WinForm、ASP.NET、等方面的项目开发、架构、管理工作。文章为作者平时里的思考和练习，可能有不当之处，请博客园的园友们多提宝贵意见。 
本作品采用知识共享署名-非商业性使用-相同方式共享 2.5 中国大陆许可协议进行许可。