public abstract void Accept( Visitor theVisitor);
public override void Accept( Visitor theVisitor)
{
theVisitor.VisitConcreteElement( this );
theVisitor.VisitConcreteElementB( this );
}
// 載入不同的Action(Visitor)來判斷
public void RunVisitor(Visitor theVisitor)
{
foreach(Element theElement in m_Context )
theElement.Accept( theVisitor);
}