Unity实例化对象脚本不重复吗？

Question

Ok I have well... 2 Questions

my first Question: If I instantiate an object, do the script stay on it, and the script starts like how they were in the beginning of the game.

my second Question: I instantiated my object, but I keep getting this error

UnassignedReferenceException: The variable target of GreenGoUp has not been assigned. You probably need to assign the target variable of the GreenGoUp script in the inspector. GreenGoUp.Update () (at Assets/Resources/Scripts/GreenGoUp.cs:23)

well basically lets say I have Envelopes(which are objects), I thorw my object(which is a prefab) into a trigger, and when it hits the trigger, the object is destroyed... and then I instantiate the object back to its starting position, But if I try to throw my object onto the trigger again. nothing happens.

The thing is I have a script in the maincamera that does a random range and puts it into a variable and depending on the number, a script runs. ill display my script now for one of the Envelopes.

MainCamera Script

using UnityEngine;
using System.Collections;

public class RandomFunction : MonoBehaviour {

    int n;
    public GameObject blueObject= null;
    public GameObject greenObject= null;
    public GameObject yellowObject= null;
    public GameObject redObject= null;
    public GameObject orangeObject= null;
    public GameObject purpleObject= null;

    void Start () 
    {
        n=Random.Range(0,1);

        switch(n)
        {
        case 0:

            greenObject.GetComponent<GreenGoUp> ().enabled = true;
            Debug.Log ("GreenGoUp Should be Working");
            break;
        }
    }
}

Script for one of the envelopes

using UnityEngine;
using System.Collections;

public class GreenEnvelope : MonoBehaviour
{
    bool isMove = false;
    public float speed = 40;
    Vector3 targetPosition;
    Vector3 currentPosition;
    Vector3 directionOfTravel ;
    public Transform target;
    public GameObject playerObject;
    GameObject Green=null;
    //public GameObject playerObject;


    void Start()
    {
        playerObject.GetComponent<OnTrig>().enabled=true;
        Debug.Log ("GreenEnvelope is now on, I should be moving");
    }

    void Update()
    {
        Debug.Log ("GreenEnvelope is now moving");
        targetPosition = target.transform.position; // Get position of object B
        currentPosition = this.transform.position; // Get position of object A
        directionOfTravel = targetPosition - currentPosition;
        if (Vector3.Distance (currentPosition, targetPosition) > .2f) {
            this.transform.Translate (
                (directionOfTravel.x * speed * Time.deltaTime),
                (directionOfTravel.y * speed * Time.deltaTime),
                (directionOfTravel.z * speed * Time.deltaTime),
                Space.World);
            transform.Rotate (new Vector3 (Time.deltaTime * 400, 0, 0));
        } 
        }
}

This script lift the envelope a little so It can be displayed to the user so he can throw it

using UnityEngine;
using System.Collections;

public class GreenGoUp : MonoBehaviour {

    Vector3 targetPosition;
    Vector3 currentPosition;
    Vector3 directionOfTravel;
    public Transform target;

    //public GameObject playerObject;
    public float speed = 40;



    void Start () {
        Debug.Log ("GreenGoUp IS WORKING");
    }


    void Update () {
        Debug.Log ("GreenGoUp IS GOING UP");
        targetPosition = target.transform.position; // Get position of object B
        currentPosition = this.transform.position; // Get position of object A
        directionOfTravel = targetPosition - currentPosition;
        if (Vector3.Distance (currentPosition, targetPosition) > .1f) {
            this.transform.Translate (
                (directionOfTravel.x * speed * Time.deltaTime),
                (directionOfTravel.y * speed * Time.deltaTime),
                (directionOfTravel.z * speed * Time.deltaTime),
                Space.World);
        } 
    }
}

This script is on the Trigger that destroys the object

using UnityEngine;
using System.Collections;

public class OnTrig : MonoBehaviour {

    ParticleSystem particle;
    public GameObject playerObject;
    public GameObject greenDestroy;
    bool isMove=false;
    public GameObject Purple;
    public GameObject Green;
    public GameObject Blue;
    public GameObject Red;
    public GameObject Orange;
    public GameObject Yellow;
    public GameObject mainCamera;



    void OnTriggerEnter(Collider col)
    {
         if(col.gameObject.tag == "Green")
        {
            Destroy(col.gameObject);
            Debug.Log ("GreenEnvelope Has Been Destroyed");
            Green = Instantiate(Resources.Load("Prefabs/greenEnvelope"),new Vector3(-11.63f,-10.49f,30.09f), Quaternion.identity) as GameObject;
            mainCamera.GetComponent<RandomFunction>().enabled=true;

        }
    }
    void OnMouseDown()
    {
        if (Input.GetMouseButtonDown (0)) {
            isMove = true;
        }

        if (isMove == true) {
            playerObject.GetComponent<GreenEnvelope> ().enabled = true;
        }
    }
}

Answer 1

I cannot answer question #1. But for question #2 to fix the error you have to assign the object for GreenGoUp. Like how this person hasn't assigned Sight in this image: .

Answer 2

Answer 1:

Yes, after instantiation of a prefab, all their scripts and their values will be copied to the instance. If however you are instantiating a runtime object (for example an object you instantiated earlier) you may run into surprises, because the new instance will copy all the values from your already initialized object, and then try to initialize it, which will likely produce inconsistent state.

Answer 2:

I assume you have Green, Blue etc. objects as instances of prefabs in your scene. For those instances, you set the "target" field of your Green(/Blue/Red)GoUp scripts to another scene object.

So far so good. Game will run and work until your Green scene object is destroyed and reinstantiated. Instantiate() will create a new instance of your Green prefab, without "target" being set, because Prefabs can not hold references to scene objects.

You'll have to reassign "target" after instantiating your object.