c# - How do I share a sqlite database between a Xamarin app and Java Android app -

as title says wanting share sqlite database between android app written in java , 1 written in c# using xamarin. can share database between 2 java apps (with of question) when try same thing in xamarin getting following error:

android.database.sqlite.sqlitecantopendatabaseexception: unknown error (code 14): not open database

i think have 2 problems.

1. i not correctly setting shared userid. placing following attribute above main activity.

   [register("my.user.id")]

   i tried using android:shareduserid="my.user.id" in manifest file throwing errors , wouldn't deploy device.

2. i don't know how whole signing of app works. maybe device sees 2 apps coming different publisher each device , not allowing 2 share context.

edit :
wanted add how signed both applications same certificate future refrence.

the android cert noramlly "c:\users\username\.android\debug.keystore" , xamarin cert noramlly in "c:\users\username\appdata\local\xamarin\mono android\debug.keystore". built xamarin app first copied debug.keystore file xamarin folder android one. (i'm sure work other way around haven't tested it)

xamarin.android not support shareduserid via applicationattribute. (i guess no 1 every filed issue it)

ref: android.app.applicationattribute

add shared user id via manifest , work fine:

example:

<application android:allowbackup="true" android:shareduserid="com.sushihangover" android:icon="@mipmap/icon" android:label="@string/app_name"></application> 

note: make sure manually uninstall both apps, add shareduserid, rebuild , reinstall both apps.

note: make sure using same signing certificate both java , xamarin apps.