static void Main(string[] args)
        {
            Model1Container context = new Model1Container();

            //第一种情况：EntityOne有导航属性EntityTwo ，新增时必需同时指定新增的EntityTwo ，否则报错：“Model1Container.EntityOnes”中的实体参与“EntityOneEntityTwo”关系。找到 0 个相关的“EntityTwo”。应有 1 个“EntityTwo”。
            var objSetOne = context.EntityOnes;
            objSetOne.MergeOption = MergeOption.NoTracking;
            objSetOne.AddObject(new EntityOne() { ID = 2, P1 = "pp1", P2 = "pp2", P3 = "pp3", EntityTwo = new EntityTwo() { T1 = "tt1", T2 = "tt2", T3 = "tt3" } });
            context.SaveChanges();

            
           //第二种情况：有些时候，我们的EntityTwo可能需要先创建，但这样执行同样报错：“Model1Container.EntityTwos”中的实体参与“EntityOneEntityTwo”关系。找到 0 个相关的“EntityOne”。应有 1 个“EntityOne”。
            var objSetTwo = context.EntityTwos;
            objSetTwo.MergeOption = MergeOption.NoTracking;
            objSetTwo.AddObject(new EntityTwo() { ID = 2, T1 = "tt1", T2 = "tt2", T3 = "tt3" });
            context.SaveChanges();

           //第三种情况：有些时候，我们的EntityTwo可能已经在之前已经创建了，此处只是查询出来，用来在需要新增EntityOne时赋值给关联属性：EntityTwo，但依旧报错：“EntityOneEntityTwo”AssociationSet 中的关系处于“Deleted”状态。如果有多重性约束，则相应的“EntityOne”也必须处于“Deleted”状态。
            var entityTwo = objSetTwo.Single(t=>t.ID==2);

            var objSetOne = context.EntityOnes;
            objSetOne.MergeOption = MergeOption.NoTracking;
            objSetOne.AddObject(new EntityOne() { ID = 3, P1 = "pp1", P2 = "pp2", P3 = "pp3", EntityTwo = entityTwo });
            context.SaveChanges();



        }