SceneStorer.cs

using UnityEngine;
using System.Collections;
using System.IO;

public class SceneStorer {

	static readonly string FILENAME = Application.persistentDataPath+"/"+"scene";

	static public void WriteToFile(int sceneID){
		//TODO
		using(FileStream fs = new FileStream(FILENAME,FileMode.Create,FileAccess.Write)){

			using(StreamWriter stream = new StreamWriter(fs)){
			
				stream.WriteLine(sceneID.ToString());
			}	
			
		}
	}

	static public int GetSaveLevel(){
		if(File.Exists(FILENAME)){

			return int.Parse( File.ReadAllText(FILENAME));
		}
		return -1;
	}

	static public int ReadFromFile(){
		//TODO
		using(FileStream fs = 
		      new FileStream(FILENAME,FileMode.OpenOrCreate,FileAccess.ReadWrite)){

			using(StreamReader stream = new StreamReader(fs)){

				string content = stream.ReadLine();
				if(content==null){

					using(StreamWriter wstream = new StreamWriter(fs)){
						return -1;
					}
				}
				else{
					 return int.Parse( content);
				}

			}

		}

	}

}