Destroy not letting me instantiate a new prefab

Unity Engine
1

EDIT: working! I’ll reply with how I worked around the issue.

Here’s the problem: When items that get picked up off the ground are destroyed (upon being picked up), I can’t instantiate a new item on the ground if I drop it out of my inventory. I’ve tried a lot it seems… I have a variable in my Item class Item.Prefab.
I set the prefab to itself in the gameobject. I know that some of the code doesn’t instantiate or use this prefab… I couldn’t get it to work with or without it.
You can see that my health prefab refers to itself here: Screenshot - e71aa342d17ffef4493f30b18f32a475 - Gyazo

Really sorry this is a lot to look through. There’s one way I can make this implementation work: Make two prefabs of every single item I have in game, set the itemprefab of first prefab (that my spawnitemscript spawns) to the second/copy prefab and then just destroy the object that is on the ground.

How do I make this work with just one prefab per item and prevent it from failing when instantiating? It tells me I already destroyed the prefab:

(startslot is just an inventory slot that has the items we want to drop).

       foreach (Item item in startSlot.Items)
        {
            GameObject temporaryDrop = (GameObject)GameObject.Instantiate(item.gameObject, playerRef.transform.position, Quaternion.identity);
            temporaryDrop.GetComponent<Item>().SetItemStatsOnDrop(item);
        }

Here’s all the code you should need to decipher and a rundown of it:

On the start of my scene, I instantiate all the items I want in my scene through this script. I just have prefabs in the slots:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SpawnAndTrackItems : MonoBehaviour
{
    public Hashtable ItemsOnGround;
    public List<GameObject> SceneItems;

    void Start ()
    {
        ItemsOnGround = new Hashtable();
        SpawnSceneItems();
    }

    private void SpawnSceneItems()
    {
        foreach (var item in SceneItems)
        {
            //GameObject prefab = item.GetComponent<Item>().prefab;
            GameObject itemRef = (GameObject)Instantiate(item, item.transform.position, Quaternion.identity);
            ItemsOnGround.Add(itemRef, item.transform.position);
        }
    }
}

Next, if a Player clicks an item on the ground, a variable (itemClicked) referencing the item script on the gameobject that was clicked is set and the following code runs:

 if (itemClicked && agent.transform.position == itemClickedDestination)
        {
            foreach (var itemName in trackItemsScript.ItemsOnGround.Keys)
            {
                if (itemName.Equals(itemClicked.gameObject))
                {
                    GameObject itemToAdd = (GameObject)itemName;
                    inventory.ClickToPickUpItem(itemClicked);
                    Destroy(itemToAdd);
                }
            }

            //itemClicked.DestroySelf();
        }

Upon looking around the forums for similar problems, I saw this and implemented it on my Item script so it will properly destroy the item?:

   public void DestroySelf()
    {
        Destroy(gameObject);
        Destroy(this);
    }

So I pick up the item and add it to my slot

    /**
     *  Everything eventually goes through "addItemPrfeab" when adding items to the slot.
     * */
    public bool ClickToPickUpItem(Item item)
    {
        if (item.maxStackSize == 1 && emptySlotCount == 0)
        {
            Debug.Log("Could not pick up " + item.itemName + ", inventory is too full.");
            return false;
        }
        else if (item.maxStackSize == 1 && emptySlotCount > 0)
        {
            Debug.Log("Picked up " + item.itemName + ".");
            PlaceEmpty(item);
            return true;
        }

        else
        {
            foreach (GameObject slot in allInventorySlots)
            {
                Slot temp = slot.GetComponent<Slot>();
                if (!temp.IsEmpty)
                {
                    if (temp.currentItem.type == item.type && temp.canAdd)
                    {
                        //add the item prefab, this is filling an empty slot with a "brand new" item
                        temp.AddItemPrefab(item);
                        return true;
                    }
                }
            }

            if (EmptySlotCount > 0)
            {
                Debug.Log("Picked up " + item.itemName + ".");
                PlaceEmpty(item);
            }

            else
            {
                Debug.Log("Could not pick up " + item.itemName + ", inventory is too full.");
            }
        }
        return false;
    }

    private bool PlaceEmpty(Item item)
    {
        if (EmptySlotCount > 0)
        {
            foreach (GameObject slot in allInventorySlots)
            {
                Slot temp = slot.GetComponent<Slot>();

                if (temp.IsEmpty)
                {
                    temp.AddItemPrefab(item);
                    temp.defaultClick = item.defaultClick;
                    temp.clickTypeOptions = item.clickTypeOptions;
                    EmptySlotCount--;
                    return true;
                }
            }
        }

        return false;
    }

The item that I add to my inventory is the item that was stored in itemClicked.

    public void AddItemPrefab(Item item)
    {
        Items.Push(item);
        this.itemName = item.itemName;
        if (Items.Count > 1)
        {
            stackText.text = Items.Count.ToString();
        }
  
        ChangeSprite(item.spriteNeutral, item.spriteHighlighted);
    }
2

In case anyone ever needs to reference how I fixed my problem… Here’s how I worked around the issue:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SpawnAndTrackItems : MonoBehaviour
{
    //public Hashtable ItemsOnGround;
    public List<GameObject> sceneItems;

    public List<GameObject> itemsOnGround;
    public List<Vector3> itemPositions;

    void Start ()
    {
        itemsOnGround = new List<GameObject>();
        itemPositions = new List<Vector3>();
        SpawnSceneItems();
    }

    private void SpawnSceneItems()
    {
        for (int index = 0; index < sceneItems.Count; index++)
        {
            GameObject itemRef = (GameObject)Instantiate(sceneItems[index], sceneItems[index].transform.position, Quaternion.identity);
            itemRef.GetComponent<Item>().sceneItemIndex = index;
            itemsOnGround.Add(itemRef);
            itemPositions.Add(itemRef.transform.position);
        }
    }
}

/**
         * Pick up the item if it was the last thing that was clicked.
         * */
        if (itemClicked && agent.transform.position == itemClickedDestination)
        {
            //get correct index
            int index = itemClicked.sceneItemIndex;
            Debug.Log("index is: "+ index);

            //add the item to the inventory using the scene items list of prefabs

            //Remove the item from the list and the position
            for(int idx = 0; idx < trackItemsScript.itemsOnGround.Count; idx++)
            {
                if(trackItemsScript.itemsOnGround[idx].GetComponent<Item>() == itemClicked && trackItemsScript.itemPositions[idx] == itemClicked.transform.position)
                {
                    inventory.ClickToPickUpItem(trackItemsScript.sceneItems[index].gameObject.GetComponent<Item>(), index);
                    GameObject item = trackItemsScript.itemsOnGround[idx];
                    Debug.Log("ClickToMove remove items from the list index:" + item.GetComponent<Item>().sceneItemIndex);
                    trackItemsScript.itemPositions.RemoveAt(idx);
                    trackItemsScript.itemsOnGround.RemoveAt(idx);
                    Destroy(item);
                }
            }
        }

public void DropItem()
    {
        //Drops an item directly below the player
        startSlot.GetComponent<Image>().color = Color.white;

        GameObject playerRef = GameObject.FindGameObjectWithTag("Player");
        Vector3 pos = playerRef.transform.position;
        foreach (Item item in startSlot.Items)
        {
            Vector3 itemHeight = new Vector3(pos.x, item.transform.position.y, pos.z);
            GameObject temporaryDrop = (GameObject)Instantiate(item.prefab, itemHeight, Quaternion.identity);
            temporaryDrop.GetComponent<Item>().SetItemStatsOnDrop(item);
            trackItemsScript.itemsOnGround.Add(temporaryDrop);
            trackItemsScript.itemPositions.Add(temporaryDrop.transform.position);

        }

        startSlot.transform.position = startPosition;
        startSlot.ClearSlot();
        Inventory.EmptySlotCount++;
    }

   /**
     *  Everything eventually goes through "addItemPrfeab" when adding items to the slot.
     * */
    public bool ClickToPickUpItem(Item item, int sceneItemIndex)
    {
        //Debug.Log("Click to pickup item index: " + item.GetComponent<Item>().sceneItemIndex);
        item.GetComponent<Item>().sceneItemIndex = sceneItemIndex;
        //Debug.Log("Click to pickup item index modified: " + item.GetComponent<Item>().sceneItemIndex);
        if (item.maxStackSize == 1 && emptySlotCount == 0)
        {
            Debug.Log("Could not pick up " + item.itemName + ", inventory is too full.");
            return false;
        }
        else if (item.maxStackSize == 1 && emptySlotCount > 0)
        {
            Debug.Log("Picked up " + item.itemName + ".");
            PlaceEmpty(item);
            return true;
        }

        else
        {
            foreach (GameObject slot in allInventorySlots)
            {
                Slot temp = slot.GetComponent<Slot>();
                if (!temp.IsEmpty)
                {
                    if (temp.currentItem.type == item.type && temp.canAdd)
                    {
                        //add the item prefab, this is filling an empty slot with a "brand new" item
                        temp.AddItemPrefab(item);
                        return true;
                    }
                }
            }

            if (EmptySlotCount > 0)
            {
                Debug.Log("Picked up " + item.itemName + ".");
                PlaceEmpty(item);
            }

            else
            {
                Debug.Log("Could not pick up " + item.itemName + ", inventory is too full.");
            }
        }
        return false;
    }

    private bool PlaceEmpty(Item item)
    {
        if (EmptySlotCount > 0)
        {
            foreach (GameObject slot in allInventorySlots)
            {
                Slot temp = slot.GetComponent<Slot>();

                if (temp.IsEmpty)
                {
                    temp.AddItemPrefab(item);
                    temp.defaultClick = item.defaultClick;
                    temp.clickTypeOptions = item.clickTypeOptions;
                    EmptySlotCount--;
                    return true;
                }
            }
        }

        return false;
    }