c++ - C++：从“BaseNode*”到“Match*”的无效转换

Answer 1

The problem is that getParent() returns a BaseNode*, which could be a pointer to any type of BaseNode - it might point to an unrelated class that also derives from BaseNode. If you're 100% sure that the parent must be of type Match, you should cast the parent to a Match* first, and then you can call getPlayer() on that:

Player* Set::getPlayer1() const{
    return dynamic_cast<Match*>(getParent())->getPlayer1();
}

If the parent isn't necessary a Match, then dynamic_cast might return NULL, so be sure to check for that.

Answer 2

I think you really need to re-organize your hierarchy and method names... This has nothing to do with your question, but in general it seems hard to fathom why Set inherits from Match. (doesn't a match have sets?)

games are composed of points, sets are composed of games and a match is composed of sets... a point is won by a player.

you should probably structure it more closely to the real world.

just my $.02

EDIT

I'd probably have a Match object that contains a map of sets (map i.e. set one, two three, etc) and the Method Player(int) rather than Player1() and player2(). Also it does not seem necessary to have a method for player in the Set class. A Set would point to a match in which it is being played.