Isolated storage

Question

Hi

I am not sure that I understand Isolated storage. I read the article http://msdn.microsoft.com/en-us/library/3ak841sy%28VS.80%29.aspx

1) Why I don't just use App data folder?

2) In the link above : "With isolated storage, data is always isolated by user and by assembly. Credentials such as the origin or the strong name of the assembly determine assembly identity. Data can also be isolated by application domain, using similar credentials." I can't think about a scenario that makes this future important.

In general I don't understand the philosophy and the need of "isolated storage" which inspire MS to create such a thing.

Thanks

Answer 1

It is created for applications running with "low trust" credentials and not only for desktop applications. Imagine you don't have permission to create files on the file system at all. In this case Isolated Storage can be very useful.

Answer 2

It's all about security.

If I know where your program is storing its critical data and I don't like you or your program, it would be easy for me to write a little app to ruin your data.

Isolated storage makes this more complicated because my application shouldn't have permission to mess around with your application's data.

Answer 3

It's all about the trust associated with an application. remember that some application run over the web, and a user might not consider an application that's running a game to be trustworthy enough to read/write data anywhere.

Being able to isolate even based on appdomain can be useful when different application might use the same 3rd party component. Consider that both a financial application (stock tracking or whatever) running from the net and a game running from the net that both use the same component to persist data. It makes sense to be able to prevent the game application from reading/writing to the financial application data.