假设我有两个类:
class PlayerManagerParent {
public function new(){
}
}
class GameManagerParent {
public var playerManager:PlayerManagerParent();
public function new(){
}
}
然后我将其子类化为
class PlayerManagerChild extends PlayerManagerParent {
public function new(){
super();
}
public function someMethod(){
}
}
class GameManagerChild extends GameManagerParent {
public function new(){
super();
this.playerManager = new PlayerManagerChild();
}
}
然后我创建 GameManagerChild
的实例并想要访问 someMethod()
:
var gameManager:GameManagerChild = new GameManagerChild();
gameManager.playerManager.someMethod();
我当然不能这样做,因为 gameManager.playerManager
是 playerManager:PlayerManagerParent
的类型,它没有定义 someMethod()
并且编译器/类型检查器给我错误。
如何在不在父类中声明 someMethod()
或将 playerManager
类型设置为 Dynamic
(这是一个选项)的情况下解决这个问题,但是我无法迭代 playerManager
中的可迭代字段,例如)?
最佳答案
您可以为此使用受约束的参数化类型:
class PlayerManagerParent {
public function new(){
}
}
class GameManagerParent<T:PlayerManagerParent> {
public var playerManager:T;
public function new(){
}
}
有了这个,你可以这样扩展:
class PlayerManagerChild extends PlayerManagerParent {
public function new(){
super();
}
public function someMethod(){
}
}
class GameManagerChild extends GameManagerParent<PlayerManagerChild> {
public function new(){
super();
this.playerManager = new PlayerManagerChild();
}
}
它允许您这样做:
var child = new GameManagerChild();
child.playerManager.someMethod();
实例:
http://try.haxe.org/#21bfC
See also:
http://haxe.org/manual/type-system-type-parameters.htmlProtip: You could even mark it as
@:generic
, which might be gain extra performance at some platforms: http://haxe.org/manual/type-system-generic.html
关于inheritance - Haxe - 如何将变量声明为父类或子类的实例,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33349718/