从继承的类在C＃转换数据类型 [英] Convert data type from inherited classes in C#

问题描述

我想了解继承我的团结项目，但似乎已经找到了限制我的设置。我得到了我的自我迷惑而写它，因为我还在学习正确理解C＃。

I am trying to understand inheritance for my unity project but seem to have found a limitation to my setup. I got my self confused whilst writing it as i am still learning to understand C# properly.

我有一组继承的类，并且他们分手基于这样我有正确的参考两个不同的行为。

I have a set of classes that inherit, and they split based on two different behaviors that way i have the correct reference.

然后我需要扮演他们这样我就可以在这些类中的一个访问方法。所以，我的结构是这样的：

I then need to cast them so i can have access to a method in one of these classes. So my structure looks like this:

public class Behaviour : Position {
    public Handler reference;

    public Behaviour(int tx, int ty, Handler refer) : base (tx,ty){
        reference = refer;
    }
    // overload
    public Behaviour(int tx, int ty) : base (tx,ty){}
}

public class Behaviour2 : Position {
      public SettingsHandler reference;

    public Behaviour2(int tx, int ty, SettingsHandler refer) : base (tx,ty) {
        reference = refer;
    }
}


public class SettingsHandler : Handler {
    public Settings level {get;set;}
}
public class Handler : MonoBehaviour{
    virtual public void Enter(List<Node> n,Vector3 p){}
    virtual public void Exit(List<Node> n, Node curNode){}
}

现在这个工作正常，直到我不得不访问Handler.Enter或Handle.Exit。然后，我就失去了对如何正确设置的类型。

Now this was working fine until i had to access Handler.Enter or Handle.Exit. Then i got lost on how to set the type properly.

所以我在做这样的事情：

So I was doing something like this:

//need to set temp :

 ??? temp;
if(path[i] is Behaviour2){
   temp = (Behaviour2)path[i];
} else {
   temp = (Behaviour)path[i];
}
temp.reference.Enter();

应该是什么类型的温度设定为在这里？

What should temp type be set to here?

我想我可能误解了继承，因为我似乎得到类型的问题。 C＃有一个解决方案 - 我不能谁卡住了唯一的一个。但我的脑子越来越糊涂试图跟随这一切。

I am thinking i might have misunderstood inheritance as i seem to get type issues. Does C# have a solution for this - i can't be the only one who has got stuck. But my brain is getting confused trying to follow it all.

推荐答案

您的问题的原因是，基类设计不当摆在首位，通过以下方式梗：

Your problem stems from the fact that the base classes are poorly designed in the first place, in the following ways:

• 层次结构是没有意义的。行为是不是一种特殊的地位。的 preFER组成继承。的

字段不应该是公开的。的使用性质，不应领域的

Fields should never be public. Use properties, not fields.

是检查是运行时类型检查;不要做多态运行时类型检查;使用虚拟方法。

"is" checks are runtime type checks; don't do runtime type checks for polymorphic behaviour; use virtual methods.

让我们重新设计你的层次。

Let's redesign your hierarchy.

abstract class MyBehaviour
{
    public Position Position { get; private set; }
    public Handler Handler { get; private set; }
    protected MyBehaviour(int x, int y, Handler handler) {
        this.Position = new Position(x, y);
        this.Handler = handler;
    }
}
class Behaviour1 : MyBehaviour {
  /* Whatever */
}
class Behaviour2 : MyBehaviour {
  /* Whatever */
}

好了，现在我们要执行的处理...

All right, and now when we want to execute the handler...

 MyBehaviour b = whatever;
 b.Handler.Enter();

完成。没有临时变量需要。没有运行时类型检查。没有如果。行为提供服务;您使用该服务。你不应该问的行为的类型，才能使用它提供的服务;如果这样做，那么可能是在设计层面。

Done. No temporary variable needed. No runtime type check. No "if". The behaviour provides a service; you use the service. You should not have to ask the behaviour its type in order to use the service it provides; if you do, something is probably wrong at the design level.

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