File I/O via Unity

If I create a project that wants to save data to an external file - how is this done in a Unity app?

e.g. Save/Load user preferences in a INI file or retain game progress, level info and anything else that might be useful to have in permanent storage.

I know I can read in text data via TextAsset but how do I write out data and control the formatting (as in a INI file)?

 

You'll have to use C#'s StreamReader and StreamWriter. Have to create your own method of writing and parsing the data though.

 

I don't suppose anyone has already done this and created a few File i/o classes/functions that we can just plug into our projects?

 

Have a look at the various functions in System.IO. Note that this is related to Mono (.net), not C#.

--Eric

 

The more I grapple with this thing, the more fragmented the information sources seem to be and the steeper the learning curve becomes. <sigh>

I dunno where on earth I got the idea this was going to be easy.

Thanks Eric for your pointer.

 

I just posted a sample StreamReader last night, check out the Road Reader class for how to read a text file from your asset bundle.

http://forum.unity3d.com/viewtopic.php?p=232729#232729

I didn't know anything about .net I/O until I started this last night, though having 30 years of programming experience helped me to figure out the best (?) direction to go as I was learning.

Managed code is a lot easier than the old way, but the learning curve is indeed fiercer. dotnet / C# programming is the summation of 40 years of API and language design and the concepts are not easy to understand.

But with practice comes competency!

 

I just made a blog post showing some code how to do File I/O in a platform-independent way (working on both PC, Mac, iOS and Android):

http://www.previewlabs.com/file-io-in-unity3d/

 

As erique pointed out here, since Unity 3.3 there's a way to do it without platform-specific code using #if statements.

Check the updated blog post for more information.

 

It is, actually. In your project settings set API Compatibility Level to .Net 2.0 and then use the standard .Net I/O functionality.

How to write files:

Code (csharp):

1. using (var writer = new BinaryWriter(File.Open(filename, FileMode.CreateNew)))
2. {
3.     writer.Write(123);
4.     writer.Write(123.456f);
5.     writer.Write("Hello, World!");
6. }

How to read files:

Code (csharp):

1. using (var reader = new BinaryReader(File.Open(filename, FileMode.Open)))
2. {
3.     var integer = reader.ReadInt32();
4.     var real = reader.ReadSingle();
5.     var text = reader.ReadString();
6. }

Also check File.ReadAllText, File.ReadAllLines, File.WriteAllText, File.WriteAllLines inside System.IO namespace.

 

I've been looking into generating levels from text files and wondered where to find the System.IO api reference. Invaluable, thanks!

 

Just follow the link

 

any clue on how to generate levels using file IO ? been trying it for a while and am lost