1 public T AddEntity(T entity)

 2 {

 3     //EF4.0的写法

 4     添加实体

 5     //db.CreateObjectSet<T>().AddObject(entity);

 6     //EF5.0的写法

 7     db.Entry<T>(entity).State = EntityState.Added;

 8     //下面的写法统一

 9     db.SaveChanges();

10     return entity;

11 }

12 public bool UpdateEntity(T entity)

13 {

14     //EF4.0的写法

15     //db.CreateObjectSet<T>().Addach(entity);

16     //db.ObjectStateManager.ChangeObjectState(entity, EntityState.Modified);

17     //EF5.0的写法

18    db.Set<T>().Attach(entity);

19    db.Entry<T>(entity).State = EntityState.Modified;

20    return db.SaveChanges() > 0;

21 }

22 public bool DeleteEntity(T entity)

23 {

24     //EF4.0的写法

25    //db.CreateObjectSet<T>().Addach(entity);

26    //db.ObjectStateManager.ChangeObjectState(entity, EntityState.Deleted);

27    //EF5.0的写法

28    db.Set<T>().Attach(entity);

29    db.Entry<T>(entity).State = EntityState.Deleted;

30    return db.SaveChanges() > 0;

31 }

32

33 public IQueryable<T> LoadEntities(Func<T, bool> whereLambda)

34 {

35     //EF4.0的写法

36     //return db.CreateObjectSet<T>().Where<T>(whereLambda).AsQueryable();

37     //EF5.0的写法

38     return db.Set<T>().Where<T>(whereLambda).AsQueryable();

39 }