public void Visit(ElementB e)
{
Console.WriteLine("ConcreteVistor1.Visit ElementB:");
e.Print();
}
public abstract void VisitElementB(ElementB elementB);
public override void VisitElementB(ElementB elementB)
{
Console.WriteLine("{0}被{1}访问", elementB.GetType().Name, this.GetType().Name);
}
public void Visit(ElementB b)
{
b.Print();
}