Silverlight isolated storage: what identifies an "application"?

Question

The docs for Silverlight's IsolatedStorageFile.GetUserStoreForApplication just say that the isolated storage is specific to the "application", and that each different application will have its own storage independent of all other "applications" (but with one quota for the entire domain).

That's great, but I haven't found anything yet that explains just what "application" is supposed to mean (either in the Silverlight docs or the regular .NET Framework docs). What information does Silverlight, in particular, use to decide that "this is application A" and "this is application B"? Does it just go off the URI to the .xap file, or what?

Answer 1

Think of it as the URL. If the URL is different the application's isolated storage will be different. You can change the metadata and such in the file all you want. Just not the filename/location of it. If I remember right you could even put a different XAP at the same URL and it will take the previous one's isolated storage.

Answer 2

According to the MSDN article for the IsolatedStorageFile class, "Isolated stores are scoped to particular assemblies." Your application is an assembly (your XAP file). An assembly has an assembly manifest that uniquely identifies it.

Answer 3

Yups, you have to types of isolated storages:

--> One is related to the xap url, in theory is that way, but I found a nasty surprise when using it.

--> The other one is common to your site (url from your site).

In theory you won't get any issue, but if you have problems with the application one (in my case when I made a new deploy the iso got wiped :-(), check out this posts:

http://www.tipsdotnet.com/TechBlog.aspx?PageIndex=0&BLID=13

http://silverlight.net/forums/p/86003/200941.aspx#200941

Answer 4

We can use Isolated Storage as a virtual file system to store data in a hidden folder on our machine in silverlight application. Silverlight application is allocated the storage of 1 MB per application but we can increase the amount of storage. This is the function to get the data in the isolated storage

Private Function LoadData(ByVal fileName As String) As String Dim data As String = String.Empty Dim isfstream As New IsolatedStorageFileStream(fileName, FileMode.Open, IsolateStorageFileObj) Dim sr As New StreamReader(isfstream) data = sr.ReadLine() Return data End Function

Eliza