这个问题，整了我一个下午

 

 

 1 public abstract class A<T> : B where T : C {

 2         //protected

 3         public A(T importer)

 4             : base(importer) {

 5         }

 6         //internal

 7         public virtual new T Importer { get { return (T)base.Importer; } }

 8           public  abstract ElementHandlerTable<T> ElementHandlerTable { get; }

 9         public override void ProcessElementOpen(XmlReader reader) {

10         }

11         public override void ProcessElementClose(XmlReader reader) {

12         }

13         public override bool ProcessText(XmlReader reader) {

14             return true;

15         }

16         //  public 

17         public override B C(XmlReader reader) {

18             string localName = reader.LocalName;

19             ElementHandler<T> handler;

20             if (ElementHandlerTable.TryGetValue(localName, out handler))

21                 return handler(Importer, reader);

22             else

23                 return null;

24         }

25     }