How To Pass Database Adapter To Another Activity?

I'm having some trouble understanding the search dialog in the Android SDK. The 'main activity' of my application provides a button. If the user clicks this button the search dialo

Solution 1:

An option would be to use a singleton and provide access to the DatabaseAdapter via a static method. Ex:

privatestaticDatabaseAdaptersWritableAdapter=null;
privatestaticDatabaseAdaptersReadableAdapter=null;

publicstatic DatabaseAdapter openForReading(Context ctx) {
    if(sReadableAdapter == null)
    sReadableAdapter = newDatabaseAdapter(newDatabaseHelper(ctx).getReadableDatabase());

    return sReadableAdapter;

}

or for write access:

publicstaticDatabaseAdapteropenForWriting(Context ctx) {
if(sWritableAdapter == null)
        sWritableAdapter = newDatabaseAdapter(newDatabaseHelper(ctx).getWritableDatabase());

    return sWritableAdapter;

}

So in your searchable activity you would write for instance:

DatabaseAdapteradapter= DatabaseAdapter.openForReading(ctx);
adapter.searchSomething();

Marco

Solution 2:

You should rather implement an ContentProvider

http://developer.android.com/guide/topics/providers/content-providers.html

They are singletons, and accessible from (almost) everywhere in your application.