How to save json file in ios?

Unity Engine
, , , , ,
1

Hey,
I want to save some data of a trainer in a sports game in a json file.
For this, i have the following function:

public List<TrainerObjectData> ListOfObjects = new List<TrainerObjectData>();

    public void saveList()
    {
        TrainerObjectData[] ObjectData = new TrainerObjectData[ListOfObjects.Count];
        ListOfObjects.CopyTo(ObjectData, 0);
        string JsonString = JSON_Helper.ToJson(ObjectData, true);
        File.WriteAllText(Application.persistentDataPath + "/Save_Data/TrainerSave.json", JsonString);
    }

The Code from the JSON_Helper is:

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

public static class JSON_Helper
{
    [Serializable]
    private class Wrapper<T>
    {
        public T[] Objekte;
    }

    public static string ToJson<T>(T[] array)
    {
        Wrapper<T> wrapper = new Wrapper<T>();
        wrapper.Objekte = array;
        return JsonUtility.ToJson(wrapper);
    }

    public static string ToJson<T>(T[] array, bool pretty)
    {
        Wrapper<T> wrapper = new Wrapper<T>();
        wrapper.Objekte = array;
        return JsonUtility.ToJson(wrapper, pretty);
    }

    public static T[] FromJson<T>(string json)
    {
        Wrapper<T> wrapper = JsonUtility.FromJson<Wrapper<T>>(json);
        return wrapper.Objekte;
    }
}

The Code of the TrainerObjectData is:

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

[Serializable]
public class TrainerObjectData
{
    public int LineID;
    public float Speed; 
    public int Level;
    public int Skin;

    public TrainerObjectData(int LineID, int Level, float Speed, int Skin)
    {
        this.LineID = LineID;
        this.Speed = Speed; 
        this.Level = Level;
        this.Skin = Skin;
    }
}

In the game I have a button that executes the “saveList()” function and a few other functions.
However, the button does not work on the iPhone. As soon as I comment out “saveList()”, the button works. But then, of course, nothing is saved.
In Editor, the function works fine, when i use File.WriteAllText(Application.dataPath + "/Save_Data/TrainerSave.json", JsonString);

What is wrong with the saveList()function?

This is the error message from XCode:

DirectoryNotFoundException: Could not find a part of the path "/var/mobile/Containers/Data/Application/A14D5957-862E-42FD-90A7-5FDB7C9DDBFD/Documents/Save_Data/TrainerSave.json".
  at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x00000] in <00000000000000000000000000000000>:0 
  at System.IO.StreamWriter..ctor (System.String path, System.Boolean append, System.Text.Encoding encoding, System.Int32 bufferSize) [0x00000] in <00000000000000000000000000000000>:0 
  at System.IO.File.WriteAllText (System.String path, System.String contents) [0x00000] in <00000000000000000000000000000000>:0 
  at Eingang_Upgrade.SetupTrainer (System.Int32 AnzTrainer, System.Int32 Level, System.Single Speed, System.Int32 Skin, System.Boolean pay) [0x00000] in <00000000000000000000000000000000>:0 
  at Eingang_Upgrade.Upgrade () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.Events.UnityEvent.Invoke () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.EventSystems.StandaloneInputModule.ProcessTouchPress (UnityEngine.EventSystems.PointerEventData pointerEvent, System.Boolean pressed, System.Boolean released) [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.EventSystems.StandaloneInputModule.ProcessTouchEvents () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.EventSystems.StandaloneInputModule.Process () [0x00000] in <00000000000000000000000000000000>:0 
UnityEngine.EventSystems.ExecuteEvents:Execute(GameObject, BaseEventData, EventFunction`1)
UnityEngine.EventSystems.StandaloneInputModule:ProcessTouchPress(PointerEventData, Boolean, Boolean)
UnityEngine.EventSystems.StandaloneInputModule:ProcessTouchEvents()
UnityEngine.EventSystems.StandaloneInputModule:Process()
2

This is just a guess, but if you already have a Save_Data folder in the persistent data path on your development computer it may work, but if that folder doesn’t already exist on the iOS device it will likely throw an exception. You need to check if all of the necessary folders in the path exist first with File.Exists, and create the folders of necessary when they are not there. Then you can try to create/open and write to a file at that location. Note that there is a wonky setting to enable to access iOS files that Unity disables by default. I’ll try to comment more specifically when I’m at my computer.

1 Like
3

That seems to solve this problem. I added the following if statement before my save statement.

    if (Directory.Exists(Application.persistentDataPath + "/Save_Data/") == false)
    {
        Directory.CreateDirectory(Application.persistentDataPath + "/Save_Data/");
    }

That seems to work.

Thank you very much :slight_smile:

1 Like
4

I’m glad it worked!

1 Like