Android Question Permision Error in Android 11

[khwarizmi]

Hi all
I want to save a text file in File.DirRootExternal, the code works fine in some versions of Android, but it does not work in Android 11 and above:

Dim rp As RuntimePermissions
    rp.CheckAndRequest(rp.PERMISSION_WRITE_EXTERNAL_STORAGE)
    Wait For Activity_PermissionResult (Permission As String, Result As Boolean)
    If Result=False Then
        ToastMessageShow("permission denied",True)
    Else
        File.WriteString(File.DirRootExternal, "fn.txt", "Some Text")
    End If

this is the error message:

mainfrm$ResumableSub_ImageView2_Clickresume (java line: 750)
java.io.FileNotFoundException: /storage/emulated/0/fn.txt: open failed: EPERM (Operation not permitted)
    at libcore.io.IoBridge.open(IoBridge.java:492)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
    at anywheresoftware.b4a.objects.streams.File.OpenOutput(File.java:449)
    at anywheresoftware.b4a.objects.streams.File.WriteString(File.java:264)
    at com.khw.stt.mainfrm$ResumableSub_ImageView2_Click.resume(mainfrm.java:750)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:267)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:207)
    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.system.ErrnoException: open failed: EPERM (Operation not permitted)
    at libcore.io.Linux.open(Native Method)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:166)
    at libcore.io.BlockGuardOs.open(BlockGuardOs.java:254)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:166)
    at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:8448)
    at libcore.io.IoBridge.open(IoBridge.java:478)
    ... 14 more
mainfrm$ResumableSub_ImageView2_Clickresume (java line: 750)
java.io.FileNotFoundException: /storage/emulated/0/fn.txt: open failed: EPERM (Operation not permitted)
    at libcore.io.IoBridge.open(IoBridge.java:492)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
    at anywheresoftware.b4a.objects.streams.File.OpenOutput(File.java:449)
    at anywheresoftware.b4a.objects.streams.File.WriteString(File.java:264)
    at com.khw.stt.mainfrm$ResumableSub_ImageView2_Click.resume(mainfrm.java:750)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:267)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:207)
    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.system.ErrnoException: open failed: EPERM (Operation not permitted)
    at libcore.io.Linux.open(Native Method)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:166)
    at libcore.io.BlockGuardOs.open(BlockGuardOs.java:254)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:166)
    at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:8448)
    at libcore.io.IoBridge.open(IoBridge.java:478)
    ... 14 more

I added to the Manifest Editor:

AddManifestText(<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="32"/>)
    AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)
AddPermission(android.permission.READ_EXTERNAL_STORAGE)

 

[DonManfred]

I want to save a text file in File.DirRootExternal

You no longer have access to this path. Use File.DirInternal

 

[khwarizmi]

So, there is absolutely no permission to save in the main memory of the device?

 

[DonManfred]

[B4X] Features that Erel recommends to avoid

Many things have changed in B4X and also in the underlying platforms. I will try to list here all kinds of (old) features that have better alternatives. B4X is backward compatible so these features still work. The recommendations are more relevant for new projects or when implementing new...

www.b4x.com

File.DirRootExternal -> ContentChooser / SaveAs
https://www.b4x.com/android/forum/threads/132731/#content

 

[khwarizmi]

Thanks a lot.