Inventory System: "The given key was not present in the dictionary."

Questions & Answers
1

Hi,

well I have been making a Inventory System, and I have all time “The given key was not present in the dictionary.” error, when I test it:

using UnityEngine;
using System.Collections;

//ItemDataBase

public class ItemScript : MonoBehaviour {

	private GameObject LoadItemPrefab(string name) {
		return (GameObject)Resources.Load ("prefabs/Items/"+name);
	}
	
	private Texture LoadItemTex(string name) {
		return (Texture)Resources.Load ("textures/Items/"+name);
	}

	void Start() {

		Inventory inv = new Inventory();
		
		InventoryItem preset;
		
		preset = new InventoryItem();
		preset.id = 1;
		preset.itemname = "Ring2";
		preset.DisplayName = "Ring of Gods";
		preset.itemtex = LoadItemTex (preset.itemname);
		preset.worldObject = LoadItemPrefab (preset.itemname);
		inv.AddNewItem(preset, preset.itemname); //Here it's assumed that is added a new value to the Dictionaru when that Script loads (that script is before than "GameGUI" that request that code.

	}

}

//Item Class

public class InventoryItem
{
	public GameObject worldObject;
	public int id;
	public string itemname;
	public string DisplayName;
	public Texture itemtex;
	public string itemtype;
	public string equipmenttype;
	public string usable;
	public float itemweight;
	public bool droppable;
	public Transform itemmodel;
	
	public int itemstacksize;
	public int itemstacklimit;
	public bool showStack;
	
	public int bagsize;
	public bool showBag;
	public InventoryItem[] BagItem;
}

public class Inventory {

   	private Dictionary<string, InventoryItem> itemsBase = new Dictionary<string, InventoryItem>();

public void AddNewItem(InventoryItem item, string name) {

	itemsBase.Add (name, item);

}

    public InventoryItem FindItem(string name) {

	return itemsBase[name];

}


}

public class GameGUI : MonoBehaviour {

public void Start() {

 InventoryItem[] InventorySlots = new InventoryItem[5];
 
 InventorySlots[3] = FindItem("Ring2"); //There is now the error: "The given key was not present in the dictionary."

}

}

Function “Find” gives me a that error, and I don’t know what can I do… Where is my error?

Can somebody checks my code?

Thanks in advance.
Bye.

I edited the code now I use a Dictionary

2

just means

items.Find (
delegate(InventoryItem Fitem)
{
return Fitem.itemname == “Ring2”;
}
);
this code presumably did not in fact find what it was send to look for

you could actually

Debug.log(items.Find (
delegate(InventoryItem Fitem)
{
return Fitem.itemname == “Ring2”;
}
))

and that should return null as well

so now you have to find out why find isnt finding it

i can see that ring2 appears to be added to inv object

i dont see where you add it to items so that it can be found in it of course you may be doing that but based on your code you should be typing

inv.find(…)

not

items.find

3

Some other part of your code must be making bad requests of your inventory system.

If you add something like this it may help you track down the problem.

public InventoryItem FindItem(string name) {

    if (!itemsBase.ContainsKey(name)){
        Debug.LogError("Unknown item name: " + name);
        return null;
    }

    return itemsBase[name];
}

Two other questions / observations:

In ItemDataBase.Start() you declare and initialize an Inventory as a function variable. Don’t you want this Inventory to persist beyond this function?

Where is the FindItem() function you access in GameGUI.Start() coming from?