Question

在WolfStateController.Start（）中我试图将State TrueState设置为继承自State的WolfIdleState。

但WolfStateController扩展了StateController。仍然不被接受。看看Start方法我写了错误信息。这应该是可能的吗？要么我缺少关于多态性的东西，要么我的语法错了。

    // STATECONTROLLER

public class StateController : MonoBehaviour 

{   
    public State<StateController> CurrentState;
}


public class WolfStateController : StateController
{
    void Start()
    {
        var idleState = new WolfIdleState();
        var keyPressDecision = new KeyPressedDecision(KeyCode.Space);

        // FOLLOWING GIVES ERROR: 
        // Cannot implicity convert WolfIdleState to State<StateController>
        keyPressDecision.TrueState = idleState; 
    }
}

// STATE

    public abstract class State<SC>  where SC : StateController 
    {
    }



   public abstract class WolfState : State<WolfStateController>
   {
   }



  public class WolfIdleState : WolfState 
   {
   }


    // DECISIONS

public abstract class StateDecision<SC> where SC : StateController
{

    public State<SC> TrueState;
}

public class KeyPressedDecision : StateDecision<StateController>
{

}

Answer 1

错误是正确的。我想你需要查看以下关于协方差和逆变的文章。

https://msdn.microsoft.com/en-us/library/dd799517(v=vs.110).aspx

您可以通过使用界面实现您想要的效果。

扩展类不接受扩展类类型

1 个答案: