Requestlegacyexternalstorage Is Not Working in Android 11 - API 30

requestLegacyExternalStorage is not working in Android 11 - API 30

But now when I targetSdkVersion 30, this no longer seems to work

That is correct. Android 11 (API 30+) requestLegacyExternalStorage=true does nothing and you can no longer "opt-out". It was available in Android 10 to give developers a transition/grace period to be able to migrate to the scoped storage model.

Option 1: Migrate data in your app whilst still targeting API 29, then once you're migrated data is compatible with scoped storage you should be able to release an update targetting API 30 - https://developer.android.com/training/data-storage/use-cases

This can come with its own problems if users skip this version and updates directly from a previous version to the latest and you're stuck with un-migrated data you can't access.

Option 2: It seems that Google sees this obvious caveat and has included a preserveLegacyExternalStorage=true option when targetting API 30 to allow you to migrate data. https://developer.android.com/reference/android/R.attr#preserveLegacyExternalStorage

Going forward you can reference this table for deciding what storage "framework" to use based on the use-case: https://developer.android.com/training/data-storage

There is a potential that some apps simply won't be able to successfully migrate, based on how they interacted with the File API as Google's solution will not encompass all current use-cases and there might not be a migration path.

For instance, I released an app a couple of years ago that allowed users to update album artwork using MediaStore and ContentResolver to update the data for the album artwork image - this was stored in shared storage. Having looked at the Android 10+ AOSP MediaProvider source code it seems that apps that used to use MediaStore to update album artwork to point to a data file no longer works, simply because the MediaProvider internally creates its own artwork in a hidden .thumbnails folder looking directly at the mp3's and using a MediaExtractor, and never references the ContentValues that were inserted to reference the artwork. So even though you can update the artwork yourself, query the MediaStore for it and see it, other apps have to use ContentResolver#loadThumbnail in API 29+ that does not reference your updated values and either creates an artwork lazily, or picks the already generated file in the .thumbnails folder. Obviously, none of this is documented, and I got a massive backlash to my app with negative reviews, yet these changes were breaking changes and completely out of my control and took me looking through AOSP source code to find that Android had fundamentally changed behaviour.

(This wasn't a rant, but an example of how these changes offered no migration path because of fundamental undocumented behaviour to AOSP).

WRITE_EXTERNAL_STORAGE when targeting Android 10

A workaround is to actually ignore the warning, as it is just informational and therefore harmless. By setting maxSdkVersion to 28 no need to worry anymore.

<uses-permission
    android:name="android.permission.WRITE_EXTERNAL_STORAGE"
    android:maxSdkVersion="28"
    tools:ignore="ScopedStorage" />

Note that using the android:requestLegacyExternalStorage flag as stated in other answers is not a solution, is just a temporary patch which will no longer work at all in Android 11 (API 30), and future versions

UPDATE, to clarify the doubts and confusions shown by some developers in the comments:

• If using the requestLegacyExternalStorage flag in Android 10 (API 29) then request the WRITE_EXTERNAL_STORAGE permission as usual.

• The flag requestLegacyExternalStorage does nothing in Android 11 (API 30), it is completely ignored, and there is not workaround for it.

• WRITE_EXTERNAL_STORAGE does not give any privileges in Android 11 (API 30), it does nothing at all, therefore in API 11 you need to set the maxSdkVersion to 29.

• If in Android 10 (API 29) you are also not using requestLegacyExternalStorage then set maxSdkVersion to 28 instead of 29.

• Starting in Android 11 (API 30), the older File API can again be used but "only" when accessing the public "shared storage" folders (DCIM, Music, etc.), or your app "private" directory. For other locations the DocumentFile API is required.

• Consider that the File API is now much slower in Android 11 (API 30), because has been refactored becoming essentially a wrapper. This is to enforce its usage just to the allowed locations. So, is no longer a fast system file API, is just a wrapper that internally delegates the work to the MediaStore. When using the File API in Android 11 or above you should consider the performance penalty hit, as according to the Android team it will be 2 to 3 times slower than if accessing directly the MediaStore.

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