Persisting Preferences with Settings

Application settings are managed by the IsolatedStorageSettings class and use the local file system. You need to be aware of a few limitations when using the settings. The settings are accessed through a dictionary with a text-based key and an object-based value. Although it may be tempting to stuff complex objects into the value, the settings service only provides lightweight serialization services, so it’s best to stick with simple primitives such as numbers and strings.

The documentation for application settings provides a warning that unexpected behavior may occur when reading and saving settings if the user has multiple instances of the application open at one time. Keep this in mind because in highly concurrent situations, you may want to use the file-based APIs instead and code with locks. An unpublished feature of the settings is that they are completely serialized and deserialized into memory any time they are accessed or modified, so it’s not wise to store large amounts of data in the settings. Access may be slow and can impact the performance of the application, and users are able to turn off isolated storage altogether.