How to use XMLSerializer and Filestream on Android? (C#)

Question

I've been using the example from this tutorial: Saving and Loading Data: XMLSerializer

to load data from an XML file saved in a "Resources" folder using the XML.Serialization library, and then create classes from the information in that file. Everything works fine when I test the code in the Unity Editor, but not when I build the game for Android.

From the example code, Filestream takes a string for the path as an argument, but since I have to include the "Assets" folder in the path (e.g. "Assets/Resources/file.xml") the game can't find the file when I build to Android (because Android doesn't see the "Assets" folder, only the "Resources" folder e.g. Resources/file) while it works fine in the Editor. Is there any way to get this to work on Android, or am I missing something about paths in Android?

Answer 1

I managed to get my game working on Android, using the StreamingAssets hint that robertbu provided (thanks), although getting it to work was a bit more involved and hacky than I'd like it to be.

I basically had to use the WWW api to begin downloading the file from my Assets/StreamingAssets folder in a Coroutine, wait for the file to finish downloading, then copy the downloaded file to the Application.persistentDataPath directory. I was then able to read the copied file using Filestream and use XMLSerializer on it. I hate how I have to download a file already included in the game in order to read from it, but I guess that's just how it is.

Here's the relevant code for those who are interested:

 using UnityEngine;
 using System.Collections;
 using System.IO;
 
 public class readTheFile : MonoBehavior {
     
     WWW www;
     
     void Start () {
         StartCoroutine("Downloader");
     }
     
     void Update () {
         
     }
 }
 
 IEnumerator Downloader ()
         {
                 #if UNITY_ANDROID && !UNITY_EDITOR //For running in Android
                 www = new WWW ("jar:file://" + Application.dataPath + "!/assets/Cards.xml");
                 #endif
                 #if UNITY_EDITOR // For running in Unity
                 www = new WWW ("file://" + Application.streamingAssetsPath + "/Cards.xml");
                 #endif
                 yield return www; //will wait until the download finishes
                 if (www.isDone == true) {
                     File.WriteAllBytes (Application.persistentDataPath + "/Cards.xml", www.bytes);
                 }        
         }

Now I can close my 50 tabs I have open about this. Or if anyone has a better answer i'd like to see it.

Answer 2

Updated to be more bug free for those interested in more dynamic solutions. Google ftw?

 using UnityEngine;
 using System.Collections;
 using System.IO;
 
 public class XMLSaveLoad : MonoBehaviour
 {
     WWW www;
 
     void Start()
     {
         StartCoroutine(SaveXML("CharacterData", false));
     }
 
     IEnumerator SaveXML(string SaveXML, bool save)
     {
         //first time run
         if (!Directory.Exists(Application.dataPath + "/XMLData/"))
             Directory.CreateDirectory(Application.dataPath + "/XMLData/");
         //create file if it's missing
         if (!File.Exists(Application.dataPath + "/XMLData/" + SaveXML + ".xml"))
             File.Create(Application.dataPath + "/XMLData/" + SaveXML + ".xml");
 
 #if UNITY_ANDROID && !UNITY_EDITOR //For running in Android
          www = new WWW ("jar:file://" + Application.dataPath + "!/assets/XMLData/" + SaveXML + ".xml");
 #endif
 #if UNITY_EDITOR // For running in Unity
         www = new WWW("file://" + Application.dataPath + "/XMLData/" + SaveXML + ".xml");
 #endif
         yield return www; //will wait until the download finishes
         if (www.isDone == true)
         {
             if (save)
                 File.WriteAllBytes(Application.dataPath + "/XMLData/" + SaveXML + ".xml", www.bytes);
         }
     }
 }

How to use XMLSerializer and Filestream on Android? (C#)

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