AppInventor won't save to my tablet's SD card

[Willis]

I am trying a simple program to enter text and save it to a file on my Samsung tablet. I can save it to Internal Storage/AppInventor/data without using the prefix"/" before my file, but what I want to do is save the file to the tablet's SD card so I can use the file in my desktop computer's applications.. I used the prefix "/' but can't find the file anywhere on the SD card. The documentation states that is where it should go. I tried adding a "sdcard" folder in my SD card drive but that didn't help. Should I use a JOIN block and add the "/" symbol to my file name?

Any ideas why I can't save to the SD card??

Confused!

[SteveJG]

By SD card, you mean the 'external SD card'   You cannot copy to the external card with the native File component.... here is a discussion about how you can copy using Taifun's file component ( https://puravidaapps.com/file.php ) and write to the external card in a limited way (see Taifun's documentation under Copy ) on some devices and operating system versions.  The extension might work for you Willis.

You might try it and see if it works on your device.

Regards,

Steve

[Willis]

Hi Steve,

Thank you for the lead on Taifun's files..They may do the trick!  I do think the description of writing to a file on a SD card on the AppInventor website is very misleading. It could be that, historically, SD meant the internal "hard drive" in a phone or tablet but has morphed into the physical card that is inserted in the device. Perhaps that should be cleared up.

[BodyMindPower]

For clarification:

From an Android point of view there are an Internal Storage and an External Storage.

1. Internal Storage

In the Internal Storage, the app package is saved:
/data/data/<app packageName>/
which can only be accessed with a rooted device.

2. External Storage

The root directory of the External Storage is:

/storage/emulated/0/

2.1. App-specific directory

In addition, there may be an app-specific directory (which can be created with Taifun's File extension: https://puravidaapps.com/file.php)

/storage/emulated/0/Android/data/<app packageName>/files)

which is saved in the External (private) Storage, but does not require READ_ / WRITE_EXTERNAL_STORAGE permissions.

This app-specific (private) folder can only be accessed by your app.

See: https://developer.android.com/reference/android/Manifest.permission.html#READ_EXTERNAL_STORAGE

2.2. Removable (micro) SD card

There may also be another external storage: a removable (micro) SD card (eg: /storage/82C3-E96C/)that can only be read (on modern Android systems).

Note: The root directory of the External Storage /storage/emulated/0/ is displayed on the device as Internal Storage (unfortunately this is a bit ambiguous).

Here is an excellent overview on this topic: https://www.dev2qa.com/android-read-write-external-storage-file-example/