Exception when saving using Application.PersistentDataPath on Windows Phone

Hello,

When saving on WP8 (Nokia 520, Unity 4.5.3f3), I get the following exception:

A first chance exception of type 'System.Exception' occurred in WinRTLegacy.DLL
Exception: Unsupported uri: c:/data/users/defapps/appdata/{c133a4f8-83a8-4125-a749-a6480c9068c2}/local\autosave.litdsavedgame
at WinRTLegacy.UnityFileStreams.OpenFile(String uri, FileMode mode)
at WinRTLegacy.UnityFileStreams.OpenFileForWriting(String uri)
at System.Xml.XmlTextWriter..ctor(String filename, Encoding encoding)
at System.Xml.XmlDocument.Save(String filename)

The file path is generated as follows:

var path = System.IO.Path.Combine(Application.persistentDataPath, filename);
...
var doc = new XmlDocument();
...
doc.Save(path);

I tried changing the "\" in the file path to "/" - same result. Anyone have any ideas? This code works fine on Windows / Android / iOS.

 

What is the value of the "filename" variable?

 

Thanks for your replies.

Replacing '/' with '\' didn't work. I am trying to use the alternate path prefixes but no success so far. I don't get the "unsupported uri" exception any more but the game acts like no data has been saved. Just to be 100% clear: Should I be replacing:

var path = System.IO.Path.Combine(Application.persistentDataPath, filename);

with

var path = "ms-appdata:///local/" + filename;

on WP8?

 

So... I tried but was not able to get a save game saving using the isostore:/ uri (no errors but the code acted like the save game wasn't there - quite possibly I was doing something wrong). I ended up adding some ifdef'd code that followed the example outlined here on how to access isolated storage with xml: http://msdn.microsoft.com/en-us/library/cc838189(v=vs.95).aspx. That worked for me!

 

@Aurimas Cernius
this is my code, and I get the same behaviour as @Marzipan

Code (CSharp):

1.  
2. private string filePath = "ms-appdata:///local/GameData.dat";
3.  
4. XmlSerializer serializer = new XmlSerializer(typeof(PlayerData));
5.             XmlTextWriter xmlWriter = new XmlTextWriter(filePath, Encoding.UTF8);
6.             serializer.Serialize(xmlWriter, playerData);
7.             xmlWriter.Close();
8.  
9. bool fileExists = System.IO.File.Exists(filePath);
10.   Debug.Log(fileExists); // This is false!!!!
11.  

No errors. It seems that the file just doesn't get saved.

 

konsnos, are you targeting WP8 or WP8.1? As Aurimas suggested, what happens if you change line 2 in your example to this:

Code (csharp):

1.  
2. private string filePath = "isostore:///local/GameData.dat"; //isostore instead of ms-appdata
3.  

 

I'm targetting WP8.1. Did the change you said. File path is "isostore:///local/GameData.dat", and got error.

Code (CSharp):

1. An exception of type 'System.IO.IsolatedStorage.IsolatedStorageException' occurred in mscorlib.ni.dll but was not handled in user code
2. Additional information: Operation not permitted on IsolatedStorageFileStream.

 

well, if it's 8.1 then it will be ms-appdata. Try this:

Code (csharp):

1.  
2. var path = @"ms-appdata:///local/";
3. var exists = System.IO.Directory.Exists(path);
4. Debug.Log(exists);
5.  

 

Result if false :-S . I didn't expect that. I don't have anything to think of right now. What do you make of this Dustin?

 

This though

Code (CSharp):

1. var path = Application.persistentDataPath;
2.             var exists = System.IO.Directory.Exists(path);
3.             Debug.Log(exists);

results to true.
Path is : "C:/Data/Users/DefApps/AppData/{72217BDD-B7FC-45F4-8749-FD3C292BE37B}/local"

 

Solved it

Code (CSharp):

1. XmlSerializer serializer = new XmlSerializer(typeof(NAMEOFCLASSHERE));
2. Stream writer = new FileStream(Application.persistentDataPath + "/GameData.dat", FileMode.Create);
3. serializer.Serialize(writer, YOURCLASSHERE);
4. writer.Close();

This works

Code (CSharp):

1. fileExists = System.IO.File.Exists(Application.persistentDataPath + "/GameData.dat");

This also works.

And to load it

Code (CSharp):

1. XmlSerializer serializer = new XmlSerializer(typeof(NAMEOFCLASSHERE));
2. TextReader textReader = new StreamReader(Application.persistentDataPath + "/GameData.dat");
3. YOURCLASSHERE= serializer.Deserialize(textReader) as NAMEOFCLASSHERE;
4. textReader.Close();

 

good

 

Use UnityEngine.Windows.File for all file operations where possible.

Also when working with paths, sometimes prefixing "file:///" helps

 

I can't seem to be able to use that for some reason. Does it need any compiler arguments? Also in the documentation it says "This is an alternative for System.IO.File class." so they must be alike.

 

What do you mean Tomas? I just have to add the using inside the cs file and I get this error in Unity Editor:

Code (CSharp):

1. Assets/Scripts/blabla.cs(9,19): error CS0234: The type or namespace name `Windows' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?
2.  

 

@konsnos I'd highly suggest you read the Unity Windows porting guide which will explain all the basics to you.

 

That seems to work. Thanks!
It should be stated in the documentation however to make it obvious.

 

it is

 

Where? I'm referring to Documention at Unity's page, here. Did I miss something? ο.Ο

 

Like here: http://docs.unity3d.com/Manual/windowsstore-missingtypes.html
and here: http://docs.unity3d.com/Manual/wp8-1-faq.html
and here: http://docs.unity3d.com/Manual/PlatformDependentCompilation.html

WinRTLegacy.dll itself isn't super well documented, but you can put the bits together. You just have to understand the platform differences and put the appropriate symbols where needed. It's impossible for Unity to document every specific scenario, so it does take a bit of work to put it all together.

The IO stuff is in the Scripting API section but I will agree it's not super clear:
http://docs.unity3d.com/ScriptReference/Windows.File.html

 

On unity 4.6.0 I could save and load a xml file without any uri. I am using FileStream to do so. The Path.Combine function is from a custom namespace, not from System.IO. It first replace / by \ before to combine the two strings to form the path.

Code (CSharp):

1. private void saveXmlDocument(XmlDocument xmlDocument)
2.     {
3.         string path = Path.Combine(Application.persistentDataPath, "gameData.xml");
4.  
5.         System.IO.Stream fileStream = File.Create(path);
6.         xmlDocument.Save (fileStream);
7.         fileStream.Dispose();
8.     }
9.  
10.     private XmlDocument loadXmlDocument()
11.     {
12.         XmlDocument xmlDocument = new XmlDocument();
13.         System.IO.Stream fileStream = null;
14.         #if NETFX_CORE
15.         fileStream = File.Open(Path.Combine(Application.persistentDataPath, "gameData.xml"));
16.         #else
17.         fileStream = File.Open(Path.Combine(Application.persistentDataPath, "gameData.xml"), FileMode.OpenOrCreate);
18.         #endif
19.  
20.         xmlDocument.Load (fileStream);
21.         fileStream.Dispose ();
22.         return xmlDocument;
23.     }