linq to DataTable有些行有些不行?

  public static DataTable CopyToDataTable<T>( IEnumerable<T> array)

        {

            var ret = new DataTable();

            foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))

                // if (!dp.IsReadOnly)

                ret.Columns.Add(dp.Name, dp.PropertyType);

            foreach (T item in array)

            {

                var Row = ret.NewRow();

                foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))

                    // if (!dp.IsReadOnly)

                    Row[dp.Name] = dp.GetValue(item);

                ret.Rows.Add(Row);

            }

            return ret;

        } 

这方法来自网上.应该很多人用的.
到转换这句话就出错了. foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))
调用:
     DataClasses1DataContext w1 = new DataClasses1DataContext();
            DataTable w3 = CopyToDataTable<b1>(w1.b1.ToList());
调试时.id列就能转换了.age列就不能转.这是怎么回事.

	[global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_id", AutoSync=AutoSync.OnInsert, DbType="BigInt NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)]

		public long id

		{

			get

			{

				return this._id;

			}

			set

			{

				if ((this._id != value))

				{

					this.OnidChanging(value);

					this.SendPropertyChanging();

					this._id = value;

					this.SendPropertyChanged("id");

					this.OnidChanged();

				}

			}

		}

		

		[global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_age", DbType="BigInt")]

		public System.Nullable<long> age

		{

			get

			{

				return this._age;

			}

			set

			{

				if ((this._age != value))

				{

					this.OnageChanging(value);

					this.SendPropertyChanging();

					this._age = value;

					this.SendPropertyChanged("age");

					this.OnageChanged();

				}

			}

		}

------解决方案--------------------
Try:

http://blog.csdn.net/q107770540/article/details/6556210