Android Q (10) ask permission to get access all storage. Scoped storage

Question

In Android 10 apps that need to access storage need to ask permission to access a concrete path. But apps like file explorer can ask permission for access to the root storage and gain permission to read/write to all storage. That is what I am trying to do.

According to Android we must use ACTION_OPEN_DOCUMENT_TREE for this. The problem I have is that everything seems correct, but the permission is not granted to the app.

  private void askAndroid10Perm()     {         Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);         intent.addFlags(                 Intent.FLAG_GRANT_READ_URI_PERMISSION                         | Intent.FLAG_GRANT_WRITE_URI_PERMISSION                         | Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION                         | Intent.FLAG_GRANT_PREFIX_URI_PERMISSION);         startActivityForResult(intent, REQUEST_CODE_OPEN_DOCUMENT_TREE);     } 

Here the user can see Android file tree and, with main storage selected, click to grant permission. "It will allow - app name - to have full access to all files currently store under this location, and any future content stored here" -> Allow

Then:

@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {     super.onActivityResult(requestCode, resultCode, data);     switch (requestCode) {         case REQUEST_CODE_OPEN_DOCUMENT_TREE:             if (resultCode == Activity.RESULT_OK) {                 Uri treeUri = data.getData();                 int takeFlags = data.getFlags();                 takeFlags &= (Intent.FLAG_GRANT_READ_URI_PERMISSION |                         Intent.FLAG_GRANT_WRITE_URI_PERMISSION);                  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {                      Log.i("TAG", "takePersistableUriPermission: " + treeUri);                     this.getContentResolver().takePersistableUriPermission(treeUri, takeFlags);                  }              }     } } 

Log:

takePersistableUriPermission: content://com.android.externalstorage.documents/tree/primary%3A

Then the app will still not have permission to access to root.

open failed: EACCES (Permission denied)

Of course I have:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 

Granted by the user.

Answer 1

Add line in Manifest

<application     android:allowBackup="true"     android:icon="@mipmap/ic_launcher"     android:requestLegacyExternalStorage="true" //Add this Line     android:label="@string/app_name">  ---------<Activity, Sevices or Recivers>----------  </application> 

Answer 2

you must add this line in your AndroidManifest.xml

android:requestLegacyExternalStorage="true"