API 26+: WRITE_EXTERNAL_STORAGE permission is always denied

Question

I have switched my app to target API 27 and now it can't be granted WRITE_EXTERNAL_STORAGE permission -- grantResult is always -1.

My app needs this permission since it doesn't use apps private external storage space (which doesn't require WRITE_EXTERNAL_STORAGE starting from API 19).

I know that in API 26 there have been behavior changes for permissions. However this doesn't explain my problem.

I'm requesting both READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE permissions in a standard way:

ActivityCompat.requestPermissions(activity, new String[] {
        Manifest.permission.READ_EXTERNAL_STORAGE,
        Manifest.permission.WRITE_EXTERNAL_STORAGE
    }, requestCode);

(both permissions are declared via <uses-permission in manifest).

The dialog appears and I click "Allow":

However inside onRequestPermissionsResult callback I'm getting a -1(denied) for WRITE_EXTERNAL_STORAGE (and 0 (granted) for READ_EXTERNAL_STORAGE).

Shouldn't the result be 0 for both since I have requested and, presumably, granted both?

I have tried to request WRITE_EXTERNAL_STORAGE alone, but in this case the dialog doesn't appear at all.

One more detail: I have just checked the merged manifest in build/intermediates/manifests/full/debug and noticed that WRITE_EXTERNAL_STORAGE permission has attribute android:maxSdkVersion="18" (there is no such attribute in my manifest). This could be happening because my app has minApiVersion=21, but I'm not sure.

@CommonsWare Yes, both are in the manifest. However, I have just checked the merged manifest in `build/intermediates/manifests/full/debug` and noticed that `WRITE_EXTERNAL_STORAGE` permission has attribute `android:maxSdkVersion="18"` (there is no such attribute in my manifest). Can this be causing the issue? — Denys Kniazhev-Support Ukraine, Apr 07 '18 at 16:47
Ah, that could be the problem. Presumably, some library has that, and it is getting merged in. Try adding `tools:remove="android:maxSdkVersion"` on your `` element, and see if that fixes it. — CommonsWare, Apr 07 '18 at 16:53
I believe read/write belong to the same permissiongroup and thus only one of them needs to be granted. But I might remember wrong on that. — Ch4t4r, Apr 07 '18 at 16:55
@Ch4t4r: They changed that behavior in 8.0 -- even though they are in the same permission group, you still need to request runtime permissions for both of them. — CommonsWare, Apr 07 '18 at 16:58
@CommonsWare it worked! Probably manifest merger has been adding `maxSdkVersion=18` because my `minSdkVersion` is `21`. This feels counterintuitive and is worth filing a bug to google. I have updated the question with the information about the merged manifest. If you post your suggestion as an answer I'll gladly accept it. Thanks! — Denys Kniazhev-Support Ukraine, Apr 07 '18 at 17:05
Glad to hear that it is working. I'll make a point to blog about this next week. — CommonsWare, Apr 07 '18 at 17:10

score 46 · Accepted Answer · answered Apr 07 '18 at 17:10

46

Somewhere along the line, you are picking up that android:maxSdkVersion="18" attribute. My guess is that it is coming from a library. Check the "Merged Manifest" tab in Android Studio, when you are editing your own manifest. It will have details of what is contributing the various elements and attributes.

android:maxSdkVersion has the effect of removing your <uses-permission> element on higher Android SDK versions, at least in terms of how runtime permissions work.

Since you need this permission for all versions, adding tools:remove="android:maxSdkVersion" on the <uses-permission> element should revert the android:maxSdkVersion="18" and give you what you expect.

answered Apr 07 '18 at 17:10

CommonsWare

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Never noticed there's actually a "Merged Manifest" tab in Android Studio, that's really nice. – Denys Kniazhev-Support Ukraine Apr 07 '18 at 17:12
2

Had 100% exact problem as @DenisKniazhev but this solution worked! I also didn't know there's something like "Merged Manifest". For those like me, the "Merged Manifest" tab can be found when you open your "AndroidManifest.xml" file right beside the "Text" tab, which is located at the bottom left (for Android Studio 3.1.3) of your Manifest file. – Edward Quixote Jul 19 '18 at 08:55
What is the solution?? – gurkan stack Sep 21 '18 at 10:02
3

If you're using HockeyApp and you're unable to write to external storage, this is why. You can also do `tools:node="replace"` – Carter Hudson Oct 16 '18 at 22:00
`HockeyApp ` make me happy – joe Dec 19 '18 at 03:09
Re:HockeyApp -- interesting -- another Microsoft acquisition. – steven smith Mar 17 '19 at 14:15

score 0 · Answer 2 · answered Jun 09 '20 at 18:37

0

I noticed a space in my permission in manifest, it was <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE "/> and I changed it to <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> and problem solved.

answered Jun 09 '20 at 18:37

صلي علي محمد - Atef Farouk

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API 26+: WRITE_EXTERNAL_STORAGE permission is always denied

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