An event can be raised only from the declaration space in which it is declared. Therefore, a class cannot raise events from any other class, even one from which it is derived. 事件只能在它被声明的声明空间(类)中使用.所以不能从任何其他类引发,即使该类是事件所在类的继承类. 那我们如何才可以引发基类中的事件,给个实例大家一…