LINQ返回的ObjectSet<T>集合是不可以修改的么？
public ObjectSet<OtherFolder> OtherFolders
        {
            get
            {
                if ((_OtherFolders == null))
                {
                    _OtherFolders = base.CreateObjectSet<OtherFolder>("OtherFolders");
                }
                foreach (var o in _OtherFolders) 
                {
                    o.FolderName = "s";
                }
                this.SaveChanges();
                return _OtherFolders;
            }
        }
------解决方案--------------------
依然可以修改：

            using (BirthdayRemindEntities2 db = new BirthdayRemindEntities2())

            {

                System.Data.Objects.ObjectSet<car> orders = db.CreateObjectSet<car>();

                foreach (car item in orders)

                {

                    item.proname = item.proname + item.ID;

                }

                db.SaveChanges();



                foreach (car item in orders)

                    item.type = item.type + item.ID;



                db.SaveChanges();

             }

------解决方案--------------------

public class ObjectSet<TEntity> : ObjectQuery<TEntity>, 

	IObjectSet<TEntity>, IQueryable<TEntity>, IEnumerable<TEntity>, 

	IQueryable, IEnumerable

where TEntity : class

可以修改的，从它的继承类上就可以看的出来

Represents a typed entity set that is used to perform create, read, update, and delete operations.

http://msdn.microsoft.com/zh-tw/library/dd412719.aspx