Answers

• NicoleLu Member, Xamarin Team Xamurai

  March 2020

  You can use

  string dbPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);

  to access the db as illustrated here: https://docs.microsoft.com/en-us/xamarin/android/data-cloud/data-access/using-sqlite-orm#basic-data-access-sample

  0
• AnonymousUser USMember ✭✭✭

  March 2020

  I generally put the database speakers.db directy inside my apk folder like that Cpodo.Cpodo/speakers.db. But as the value of the variable dbPath:

  string dbPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
  var connection = new SQLiteConnection(System.IO.Path.Combine(dbPath, "speakers.db"));
  

  runtime is /data/user/0/Cpodo.Cpodo/files I decided to put the database in that folder Cpodo.Cpodo/files/speakers.db. When I run the app I get the following exception no such table: speakers. When I give the following value to the databasesPath variable:

  string databasesPath = Android.OS.Environment.ExternalStorageDirectory.ToString() + "/Android/data/Cpodo.Cpodo/files";
  var connection = new SQLiteConnection(System.IO.Path.Combine(databasesPath, "speakers.db"));
  

  I don't get exceptions, I am able to connect to the database. The value of databasesPath runtime is "/storage/emulated/0/Android/data/Cpodo.Cpodo/files"

  0
• NicoleLu Member, Xamarin Team Xamurai

  March 2020 Accepted Answer

  For /storage/emulated/0/Android/data/Cpodo.Cpodo/files, you can use:
  this.GetExternalFilesDir(null).AbsolutePath;

  But please do notice that: as Android doc says here: if files are in a directory within external storage, other apps can get access to the files.

  I'm wondering why /data/user/0/Cpodo.Cpodo/files this folder doesn't work for you, since it's working good on my side. Please let me know if you want to further look into this questions and provide some extra informations that may be related.

  5
• AnonymousUser USMember ✭✭✭

  March 2020 edited March 2020

  Originally I intended to put the database directly in /storage/emulated/0/Android/data/Cpodo.Cpodo folder. Can I get that path programatically and is files folder the most appropriate place for databases or if they are directly in the apk folder it's also OK?

  0
• NicoleLu Member, Xamarin Team Xamurai

  March 2020 Accepted Answer

  I can get to /data/user/0/packagename with:

  this.DataDir.AbsolutePath

  But didn't find programatical way to the external data directory.
  As Android storage guideline declared, data/files that's specific for your app can be stored either in internal storage(/data/user/0/packagename/...) or external storage(/storage/emulated/0/Android/data/packagename/...), both files will be removed on app uninstall. The only difference is that whether other apps are able to get access to your file. For database files, I think it would be better if you store it in the internal storage.

  For which folder is the best for storing database file, actually when I go through guides for Xamarin Forms/Android database, there's code using LocalApplicationData, that is /data/user/0/packagename/files/.config:

  Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)

  as well as Personal folder /data/user/0/packagename/files:

  Environment.GetFolderPath (Environment.SpecialFolder.Personal)

  So I think files and files/.config will surely be ok to store database file. For other folders, as long as it's not for specific use, then whether it's appropriate for databse, it's up to you.

  Hope it helps.

  5
• AnonymousUser USMember ✭✭✭

  March 2020 edited March 2020

  By the way I don't have any external storage on my phone. I don't know why it is showing that the apk is located in /storage/emulated/0/Android/data/Cpodo.Cpodo.
  I don't connect to the db from an activity but from normal class DatabaseHelper where I have the method GetAllFromTable(where I do the connection). In the DatabaseHelper class I don't have access to GetExternalFilesDir(null).AbsolutePath method. Can I get /storage/emulated/0/Android/data/Cpodo.Cpodo path programatically in a normal class without passing to that class an instance of an activity. I don't want the DatabaseHelper class to be coupled with activities etc. I just want to use it in an activity just to get a list of object(database records)?

  0
• NicoleLu Member, Xamarin Team Xamurai

  March 2020

  I didn't find something similar with GetExternalFilesDir(null).AbsolutePath when not using an activity, In this case, I think it would better for you to use the internal storage since it is dependent from Activity.

  0