System.IO.IsolatedStorage allows you to access
an isolated area of a filesystem for your application. This is useful
when access to the System.IO classes is not
possible. The security settings of the .NET Framework prohibit web
applications and downloaded controls from accessing the local
filesystem directly, but those settings allow them to use
Applications' storage areas are isolated from one
another, so anything in isolated storage is protected from untrusted
applications. The size of isolated storage is limited, so an
untrusted application cannot create a denial-of-service condition by
filling your hard disk with data.
When you use isolated storage, the runtime sets aside disk space for
a given level of isolation (specified using
IsolatedStorageScope). If you use Windows 2000 or
XP, <SYSTEMDRIVE>\Documents and
Settings\<user>\Application Data contains the
isolated storage area if roaming is turned on, and
Settings\<user>\Local Settings\Application Data
contains the storage area if roaming is not on. Applications can use
this area as a data store for their particular persistence needs.
Figure 32-1 shows the inheritance diagram for this
namespace. For more information, see Section 10.4 in Chapter 10.