How to save a list of items?

Question

So I understand the basics of PlayerPrefs and how to save data, one thing I can't figure out though is how to save a list of items. For example: equipped items, items in inventory, etc. I was thinking a 'forloop' would work for this but so far I have not been successful. Can anyone give me an idea of how to go about this? Any input is much appreciated. Thank you!

Answer 1

Best Answer

Answer by flamy · Feb 23, 2012 at 12:31 PM

with playerprefs there are two ways to do it... one is using a for loop as you tried. Like the below

for(int i=0;i<TotalInventoryItem;i++)
{
    PlayerPrefs.SetString("InventoryItem"+i,"*insert your item value or name*");
}

even while retrieving you can do the same. This is one method..

But if the Items in inventory is an array or list!! you can easily save and retrieve it in this method. (unless number length or array is way too big!!)

for instance let the array name be Inventory

int[] Inventory; string temp="";

for(int i=0;i< Inventory.Length;i++)
{
     if(i!=Inventory.Length-1)
        temp+=Inventory[i].ToString()+"*";//note that the last character you add
                                    //is important
     else
        temp+=Inventory[i].ToString();
}

PlayerPrefs.SetString("InventoryItems",temp);

While retriving you have to just get the InventoryItems key and slplit it and explode it back, like this

string temp=PlayerPrefs.GetString("InventoryItems"); string[] tempArray=temp.Split("*".ToCharArray());

for(int i=0;i<tempArray.length;i++)
{
   Inventory[i]=System.Int32.Parse(tempArray[i]);
}

Hope it is clear:)

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flamy · Feb 23, 2012 at 12:34 PM 0

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Forgot to add that the second method will work with all datatypes (not only int)

ObviouslyInsane · Feb 23, 2012 at 09:36 PM 0

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Wow, thank you very much guys. You gave far more info that what I was even hoping for. I just woke up and haven't had a chance to try anything yet but I'm sure i'll have no problem figuring it out now.

Answer 2

Answer by Eric5h5 · Feb 24, 2012 at 10:02 AM

Use ArrayPrefs2 (as long as it's arrays of basic types like Vector3, String, etc.).

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ObviouslyInsane · Feb 24, 2012 at 10:44 AM 0

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Thank you Eric, I'm headed to bed now but I will definitely look into that in the morning. One more thing I think I should mention though now that I think of it is the items in the list I am trying to save contain both string and int values. Will using just SetStringArray or SetIntArray work for saving both values? Sorry if that's confusing I can't think straight anymore.

ObviouslyInsane · Feb 24, 2012 at 10:48 AM 0

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Also the data is in one of my own Classes if that makes a difference. (Wasn't letting me edit my last comment)

Eric5h5 · Feb 24, 2012 at 10:52 AM 0

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SetStringArray only works with String[] arrays, and SetIntArray only works with int[] arrays. You could use the techniques in that script to make a custom function, or you could convert the data in your classes to String[] and int[] arrays before saving, then convert the String[] and int[] arrays to your classes when loading.

andybak · Feb 17, 2018 at 04:21 PM 0

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Fixed link: http://wiki.unity3d.com/index.php/ArrayPrefs2

Answer 3

Answer by ObviouslyInsane · Feb 24, 2012 at 05:34 AM

Ok I guess I can use a little more help. I should have mentioned I'm using JS and trying to save items in a List. Here's what I have so far:

 import System.Collections;
 var Inventory;
 var temp : String = "";
 var tempArray : String[];
 var i : int;
 
     //SAVE DATA 
      Inventory = GameObject.Find("GUIElements").GetComponent("Inventory").inventory;
 
     for(i = 0; i < Inventory.Count; i++) {
     
             if(i != Inventory.Count -1)
             temp += Inventory.ToString()+"*";
                                        
             else
             temp += Inventory.ToString();
             }
     
             PlayerPrefs.SetString("InventoryItems",temp);
     
 
     //LOAD DATA
      Inventory = GameObject.Find("GUIElements").GetComponent("Inventory").inventory;
 
         temp = PlayerPrefs.GetString("InventoryItems");
         tempArray = temp.Split("*".ToCharArray());
         
         for(i = 0; i < tempArray.Length; i++)
     {
       Inventory[i] = System.Int32.Parse(tempArray[i]); <<<ERROR HERE
     }

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flamy · Feb 24, 2012 at 05:51 AM 0

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i made 2 typos there sorry in the first for loop... i have updated in my answer now and regarding missing method exception add

import System.Collections;

in the beginning of the file.... also while declaring use String, like

var temp:String; var tempArray:String[];

and in your last for loop condition it is tempArray.Length not Count

ObviouslyInsane · Feb 24, 2012 at 08:41 AM 0

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Ok, I changed everything as you said and added the import System.Collections but I am still getting that same error. In case it makes any difference I want to clarify that the variable (Inventory) I am referencing is a list and not an array.

Vagonn ObviouslyInsane · Nov 13, 2015 at 10:27 AM 0

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use

Inventory[i] = int.Parse(tempArray[i]);

flamy · Feb 24, 2012 at 09:03 AM 0

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hmm never had this problem it work fine for me... i copied ur code and even it works fine here... can copy the present code here?

ObviouslyInsane · Feb 24, 2012 at 09:57 AM 0

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Certainly, I updated the code in my second post to show what I have now. I'm not getting the Missing Method error anymore, but I am getting a new one at the line I marked. It says 'FormatException: Input string was not in the correct format'

flamy · Feb 24, 2012 at 10:54 AM 0

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for(i = 0; i < Inventory.Count; i++) {

         if(i != Inventory.Count -1)
         temp += Inventory[i].ToString()+"*";      <<this line

         else
         temp += Inventory[i].ToString();          <<this line
         }

         PlayerPrefs.SetString("InventoryItems",temp);

you have to add i there, is that done also try printing the temp vatiable when u save it and also when u retrive it

Answer 4

Answer by toomas008 · Feb 23, 2012 at 04:13 PM

If the data that you're trying to serialize is in your own classes, then you may look into .NET serialization. But keep in mind, that it doesn't work when you want to store MonoBehaviours or other class instances from Unity namespaces, because deserialization tries to do "new" on MonoBehaviours and not Instantiate() as Unity requires.

A very tiny example of the concept: http://blog.kowalczyk.info/article/Serialization-in-C.html

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How to save a list of items?

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