问题
As a developer, I have applications already published on the market. When users download the new version, I want the application to clean its states ( SharedPreferences , SQLite schema ... ). I read about SQLiteOpenHelper. I suppose when I'm loading a new .apk on the device from Eclipse, the app still keeps its previous SharedPreferences . If the DB schema changed, the app will crash.
Is it possible to trigger a "clean states" when the application is being upgraded from the market ?
回答1:
To your question, you should be able to trigger a database update using SQLiteOpenHelper OnUpgrade (change DATABASE_VERSION in your class) and either call a function from there to clear the preferences or add a flag to the db for this and do it in your main program.
来源：https://stackoverflow.com/questions/7077988/how-to-reset-an-application-states-when-upgrading-from-the-market