B4A Class Manage External Storage - access internal external storage >= SDK 30

Erel · May 4, 2021

I've added this to the list of resources: https://www.b4x.com/android/forum/threads/saveas-let-the-user-select-a-target-folder.129897/#content

As you wrote, this solution is mostly for non-Google Play apps. The policy is explained here: https://support.google.com/googleplay/android-developer/answer/10467955

Xfood · May 4, 2021

Small change to read the package name
Thank you @agraham
Thank you @Erel

B4X:

Public Sub GetPermission
    If HasPermission Then
        RaiseEvent
        Return
    End If
    Dim in As Intent
    ' Be sure to reference your app package name in "pakageg:xxx"                                             ^^^^^^^^^^^^^^^^^
    in.Initialize("android.settings.MANAGE_APP_ALL_FILES_ACCESS_PERMISSION", "package:" & Application.PackageName)
    StartActivityForResult(in)
End Sub

scottie · Jul 22, 2021

Using your great example. I'm still not able to do simple file operations
I checked app setting and I do have permission: Allow management of all file
running Android 11
Just to test, All I did was add a button and textbox to this example.

example:

B4X:

Private Sub Button2_Click
edittext1.text = "/Android/data/lb.myapp.lbochs/files"   NOTE:  this is NOT my app folder!

    Try
    File.WriteString(File.DirRootExternal & EditText1.Text,"scott.txt","scott was here")
    Catch
        MsgboxAsync("didn't work: " & File.DirRootExternal & EditText1.Text & "/scott.txt","")
    End Try
End Sub

file.copy(...) wont work either

What am I doing wrong?

-Scott

agraham · Jul 22, 2021

From
Android 11 storage FAQ. First introduced in Android 10, scoped… | by nandana | Android Developers | Medium

For these cases, we have added the MANAGE_EXTERNAL_STORAGE permission to give access to all files on external storage, except the Android/data and Android/obb directories. To learn more about related Google Play guidelines, read the updated policy from the Policy Help Center.

my boldening

scottie · Jul 22, 2021

Thanks for your reply. I read your link. Basically that says we cant access /Android/data anymore. but I really want to. Haa
apps like x-plore can do it, so why cant we? I've even tried adding
permissions
REQUEST_INSTALL_PACKAGES
MANAGE_UNKNOWN_APP_SOURCES

and enabled it in app settings
didn't work

agraham · Jul 22, 2021

Several File Managers can do this by exploiting a loophole that Google may well close at some time. Look at this page and follow the 'as written here' link.
No access to Android/data on Android 11 – Lonely Cat Games

They seem to be using
ExternalStorage - Access SD cards and USB sticks | B4X Programming Forum
and getting the user to select the Android folder as root. I haven't tried this myself but you could give it a go.

scottie · Jul 22, 2021

Good thing I'm off from work today

This works in Android 10, but not Android 11.

b4a programmer · Aug 8, 2021

Hi
Thanks for your useful source. This source works fine, but I still have trouble copying a file to the Android / data folder, and Android 11 does not allow access to this folder. What can I do about this problem?
Please help

ziwalig · Aug 22, 2021

Hello Agraham

I put your example in my app and I can share everything too. Now how can I access my database in a folder? When initializing it comes this error. Sorry for the bad English it is a deepl.com translation.

android.database.sqlite.SQLiteCantOpenDatabaseException: Cannot open database '/storage/emulated/0/Test/dbRE.db3': File /storage/emulated/0/Test/dbRE.db3 is not readable
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:365)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:226)
at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:737)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:284)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:251)
at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:1392)
at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:1337)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:1007)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:946)
at anywheresoftware.b4a.sql.SQL.Initialize(SQL.java:44)
at ch.ziwalig.replikateinrichten.msqlitedb._dbinitialisieren(msqlitedb.java:35)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:193)
at anywheresoftware.b4a.shell.DebugResumableSub$RemoteResumableSub.resume(DebugResumableSub.java:22)
at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:267)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:137)
at anywheresoftware.b4a.BA$2.run(BA.java:387)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8587)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 2062 SQLITE_CANTOPEN_EACCES[2062]): Could not open database
at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:337)
... 28 more

agraham · Aug 22, 2021

No idea, but I don't think it is anything to do with the permission. Looks more like a corrupt database.

drgottjr · Aug 24, 2021

attn: @zwalig
android 11, sdk30

for what it's worth,
1) i put an sqlite3 db in dir.assets
2) i copied it to dir.rootexternal
3) i opened it and made a simple query
cap1.png image attached.

4) i created a "Test" folder in dirrootexternal
5) i copied the db from assets to the Test folder
6) i opened it and made a simple query
cap2.png image attached.

cap3 shows the db in dirrootexternal
cap4 shows the db in dirrootexternal/Test

not sure how you implemented the example.

swChef · Nov 7, 2021

agraham said:
Google seems intent on dumbing down Android to the point of uselessnes to me. I think of my devices as little computers and I want a proper file system on them, not the limited tortuous things that Google offers and that I don't understand, ContentChooser, FileProvider, ... I'm getting old and can't cope with complications like that!

So here is a class that lets apps on SDK 30 and higher devices treat the file store as a real file store and not some dumbed down abstracted thing. ?

It uses a new permission that Google will not allow for most Play Store apps.
Manage all files on a storage device | Android Developers
As I will never have apps in the Play Store this worries me not one jot

The class uses code stolen from Erel's ExternalStorage class to provide a similar API - thank you Erel ?
ExternalStorage - Access SD cards and USB sticks | B4X Programming Forum

FYI just tried this on my Pixel 6 on Android 12. B4A is using android-30\android.jar.
/storage/emulated/0 returns -1
the File Dialog list is empty.
Tried targeting 28 and dropping the 'legacy' (which as I understand it only helps if the specific app had been installed earlier and had access), didn't work.

X-Plore can still access s/e/0, and Android/data/[etc] however.
I've never used X-Plore before on any device.

agraham · Nov 8, 2021

Works fine on my Pixel 4a with Android 12. Did you actually enable the permission when prompted?

swChef · Nov 8, 2021

agraham said:
Works fine on my Pixel 4a with Android 12. Did you actually enable the permission when prompted?

yes

agraham · Nov 8, 2021

No idea I'm afraid. As far as I know it should just work - as it seems to for me.

swChef said:
/storage/emulated/0 returns -1

Not sure what you mean by this but -1 is the dialog OK code so you pressed the OK button.

swChef · Nov 8, 2021

agraham said:
No idea I'm afraid. As far as I know it should just work - as it seems to for me.

Not sure what you mean by this but -1 is the dialog OK code so you pressed the OK button.

minor. just the toast message after hitting ok with no file selected in the example. there were no files to select.

Peter Simpson · Dec 26, 2023

agraham said:
Google seems intent on dumbing down Android to the point of uselessnes to me. I think of my devices as little computers and I want a proper file system on them, not the limited tortuous things that Google offers and that I don't understand, ContentChooser, FileProvider, ... I'm getting old and can't cope with complications like that!

Hear hear Andrew.
I understand securing internal drives and folders etc, but that's about it. But once I plug in a standard everyday USB dive of one sort or another, I want just want it to act like a normal external drive and not like a highly secure online bank account where you need to jump through all these new fangled bells and whistles just to load a basic bitmap in a imageview.

I'm going to give your class a quick blast just too see what it does exactly...

aeric · Jan 17, 2024

Hi Andrew,

Thanks for sharing the library.
I want to buy you a coffee but PayPal does not allow donation from my country.
Could you send me your PayPal email through PM as I can't send you a PM?

agraham · Jan 18, 2024

aeric said:
I want to buy you a coffee

Thanks for the kind thought but as we say here "Have it on me". Your thanks are enough.

B4A Class Manage External Storage - access internal external storage >= SDK 30

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