将游戏对象附加到继承自单行为的脚本

Question

I have my game organized by states as follows: BeginState PlayState WonState LostState

and a script to manage them called StateManager.cs:

public class StateManager : MonoBehaviour 
{
    private IStateBase activeState;

    void Start () 
    {
        activeState = new BeginState (this);
    }

    void Update () 
    {
        if (activeState != null)
            activeState.StateUpdate();
    }

    void OnGUI()
    {

        if (activeState != null)
            activeState.ShowIt();    }

    public void SwitchState(IStateBase newState)
        {
        activeState = newState;
        }
}

The problem is when I am attaching a script component to a game object this statemanager.cs script is only I use because it is classified as Monobehaviour.

For example I want to use the Playtstate.cs, but I am not able.

using UnityEngine;
using Assets.Code.Scripts;
namespace Assets.Code.States
{
    public class PlayState : IStateBase
    {
    private StateManager manager;


    public PlayState (StateManager managerRef)
    {
        manager = managerRef;
        Debug.Log ("Constructing PlayState");

    }
    public void StateUpdate()
    {
        if (Input.GetKeyUp(KeyCode.Space))
        {
            manager.SwitchState(new WonState (manager));
        }

        if (Input.GetKeyUp(KeyCode.Return))
        {
            manager.SwitchState(new LostState (manager));
        }
    }

Despite PlayState being an IStateBase instance it is not considered Monobehaviour, so I cannot add a button that is exclusive to this state. How can I get around this?

Answer 1

To be able to attach any Script to GameObject you need to have your script or any class in its inheritance tree to inherit from MonoBehaviour . To be able to assign its public fields from Inspector , you need to also mark it as [Serializable] . Please note that your IStateBase is nowhere to be seen as inheriting from MonoBehaviour . Actually we can't see its implementation at all.

Let's see all the general possibilites we have in Unity3D :

Inherit from other class that inherits from MonoBehaviour

//Works because it inherits from class inheriting MonoBehaviour
public class TestScript : BaseTest
{
}

//This will also be assignable from Inspector
public class BaseTest : MonoBehaviour
{
}

Inherit from other abstract class that inherits from MonoBehaviour

//This will also work as we still have MonoBehaviour in a root of our inheritance
public class TestScript : BaseTest
{
}

//This will not be assignable from Inspector
public abstract class BaseTest : MonoBehaviour
{
}

Inherit from interface that inherits from MonoBehaviour

Well, interface can't inherit from class or abstract class, only from other interface so it won't work anyway.