12-07-2011 01:53 AM
12-07-2011 04:11 AM
12-07-2011 05:58 AM
If persistent storage on the Blackberry is new to you, here are some links to help you understand it.
12-07-2011 06:04 AM
Actually i know about persistent storage. But my problem is , if i upgrade the Application all persistent data getting loss in new version app . I need that old persistent data values in new version app also.
12-07-2011 06:56 AM - edited 12-07-2011 08:53 AM
One of the things you should know about persistent store is that if the classes you put in PersistentStore change with the new Application, then you have rendered the data in the old class unreadable, so your only option is to delete the app (deleting the old class data) and install the new app.
So use generic classes or make compatible changes and you will be able to upgrade your app.
For example, if you persist a HashTable, and you add String values to it, then this doesn't change regardless of the number of String values you add. But if you store a custom class and you add another variable to that class, then it has changed and will be incompatible.
Does that help?