Android Question External Storage Error !

[Alberto Gaia]

Ho Guys, my problem is: (b4a-7.80)
- I'm using External Storage (V1.03) example to access USB drive and copy files from it.
So , with my Mass Storage connected, i try PickFolder buttom and follow error comes..:


*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
Can use persistant uri!
Error occurred on line: 150 (ExternalStorage)
java.lang.ClassNotFoundException: android.support$v4$provider$DocumentFile
at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:288)
at anywheresoftware.b4j.object.JavaObject.InitializeStatic(JavaObject.java:74)
at b4a.example3.externalstorage._getpickeddir(externalstorage.java:455)
at b4a.example3.externalstorage._setpickeddir(externalstorage.java:528)
at b4a.example3.externalstorage._selectdir(externalstorage.java:137)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:339)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:170)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
at android.view.View.performClick(View.java:5201)
at android.view.View$PerformClick.run(View.java:21163)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
** Activity (main) Pause, UserClosed = true **
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **

Regards, Albert

 

[DonManfred]

Upload a small project which shows the issue.
My guess is that you did not successfully implemted ExternalStorage Class. Missing

#AdditionalJar: com.android.support:support-core-utils

?
If not missing then, i guess, you are not using AndroidX

1. Update to B4A 9.8. No reason not to upgrade; it is free.
2. Reinstall everything new (including SDK).

follow the Instructions here:

B4A – The simple way to develop native Android apps

B4A includes all the features needed to quickly develop any type of Android app. B4A is used by tens of thousands of developers from all over the world, including companies such as NASA, HP, IBM and others.

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