EF Detatch

gistfile1.cs

 static int[] Detach<TEntity>(
        this IUnitOfWork unitOfWork, Func<TEntity, bool> where, Func<TEntity, int> getKey = null)
		    where TEntity : EntityObject
	    {
			if (!(unitOfWork is ObjectContext))
			{
				return new int[0];
			}
 
		    var objectContext = ((ObjectContext)unitOfWork);
		    var objectStateManager = objectContext.ObjectStateManager;
		    var entitiesToDetach = objectStateManager
			    .GetObjectStateEntries(EntityState.Modified | EntityState.Unchanged | EntityState.Deleted)
			    .Where(entry => entry.Entity != null && entry.Entity.GetType() == typeof(TEntity) && @where((TEntity)entry.Entity))
			    .Select(entry => (TEntity)entry.Entity)
			    .ToList();
			foreach (var entity in entitiesToDetach)
			{
				objectContext.Detach(entity);
			}
 
		    if (getKey == null)
		    {
			    return new int[0];
		    }
		    return entitiesToDetach.Select(entity => getKey(entity)).ToArray();
	    }