Throws Exception “Operation not permitted on IsolatedStorageFileStream” When read from isloated storage

Question

In my app I have to download all the images from the remote server and display it in a list view .When i tried to extract the images from isolated storage I have got an exception

"Operation not permitted on IsolatedStorageFileStream"

.here is my code

public static object ExtractFromLocalStorage(Uri imageFileUri)
    {

        byte[] data;
       string isolatedStoragePath = GetFileNameInIsolatedStorage(imageFileUri);       //Load from local storage
        if (null == _storage)
        {

             _storage = IsolatedStorageFile.GetUserStoreForApplication();
        }
         BitmapImage bi = new BitmapImage();
  //HERE THE EXCEPTION OCCURS
        using (IsolatedStorageFileStream sourceFile = _storage.OpenFile(isolatedStoragePath, FileMode.Open, FileAccess.Read))
        {
            data = new byte[sourceFile.Length];

            // Read the entire file and then close it
            sourceFile.Read(data, 0, data.Length);
         // Create memory stream and bitmap
        MemoryStream ms = new MemoryStream(data);

        // Set bitmap source to memory stream
        bi.SetSource(ms);
            sourceFile.Close();


        }
        return bi;
    }

the above function is used to get the bitmap image from isolated storage,and my model class is

public class Details
{ 
  public string id { get; set; }
  public string name { get; set; }
  public Uri imgurl { get; set; }
  [IgnoreDataMember]
  public BitmapImage ThumbImage{get;set;}
}

and i am using a singlton class to call the function to get image.

public class SingleTon
{
    static SingleTon instance = null;

    private SingleTon()
    {

    }

    public static SingleTon Instance()
    {


                if (instance == null)
                {
                    instance = new SingleTon();
                }
                return instance;


    }

    public BitmapImage getImage(Uri uri)
    {
        lock (this)
        {
            BitmapImage image = new BitmapImage();
            image = (BitmapImage)CacheImageFileConverter.ExtractFromLocalStorage(uri);
            return image;
        }
    }
    public void writeImageToIsolatedStorage(Uri imageUri)
    {
        lock (this)
        {
            CacheImageFileConverter.DownloadFromWeb(imageUri);
        }
    }
}

this is the code for set the image to the object

 SingleTon singleton = SingleTon.Instance();
 List<(Details > datalist = new Details()
 foreach (Details items in DataList)
        {

    items.ThumbImage = singleton.getImage(items.imgurl );
    datalist.add(items);    

    }

please any one help me with a solution.

There seem to be way too much code for exception you are facing... At least add comment where you get an exception AND remove insane amount of empty lines... — Alexei Levenkov
@MattLacey using (IsolatedStorageFileStream sourceFile = _storage.OpenFile(isolatedStoragePath, FileMode.Open, FileAccess.Read))//here the exeption occurs — Sujiz
FYI, "Singleton" is one word not two. It's also a terrible name for a non-generic class as it doesn't describe what the class does (other than that there's only one instance of it) — Richard Szalay
Also, your call to sourceFile.Close() is redundant as it will be closed as part of the using block. — Richard Szalay

Richard Szalay Richard Szalay · Accepted Answer · 2013-01-24T02:22:21

This exception usually occurs if you haven't closed a previously open Stream to the same file. Check CacheImageFileConverter.DownloadFromWeb and make sure your output Stream is wrapped in a using block.

That exception might also be thrown if the file doesn't exist, but I'm not 100% sure. Maybe through in a call to IsolatedStorageFile.FileExists() before you open it just to be sure.

Throws Exception “Operation not permitted on IsolatedStorageFileStream” When read from isloated storage

1 Answers