Android 6: cannot share files anymore?

Question

I am sharing an image, and this code works properly for devices before Android 6:

Intent shareIntent = new Intent(Intent.ACTION_SEND);
shareIntent.setType("image/*");
Uri uri = Uri.fromFile(new File(mFilename));
shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
mContext.startActivity(Intent.createChooser(shareIntent, mChooserTitle));

However I get the toast error "can't attach empty files" when I try to share using Android 6.

I verified that the file exists and it's not zero-length.

Anyone has a solution for this?

Are you getting this `Toast` before or after the chooser? If after, what app did you choose? Also, where is `mFilename` pointing, exactly? — CommonsWare, Oct 06 '15 at 23:05
After the chooser, it happens with every app I tried. At least with Gmail and Hangout. — Daniele B, Oct 06 '15 at 23:06
mFilename is inside the `getExternalCacheDir()`, starting with `/storage/emulated/0/Android/data/` — Daniele B, Oct 06 '15 at 23:07
Have you run Gmail and Hangouts yet, on their own? If not, they will not have access to external storage, until you (the user) go through their runtime permissions request logic. — CommonsWare, Oct 06 '15 at 23:07
Yes! you are right!!!!!!!!!!!!!!!!!!!!!!!! I enabled the external storage permission of Gmail, and now it works!!!!!! — Daniele B, Oct 06 '15 at 23:10
although it seems very silly to me that Gmail doesn't ask for the permission when I attempt to share — Daniele B, Oct 06 '15 at 23:11

score 43 · Answer 1 · edited Oct 08 '15 at 06:52

I solved it by implementing a FileProvider, as suggested by @CommonsWare

You first need to configure a FileProvider:

first, add the <provider> to your file manifest XML

<provider
    android:name="android.support.v4.content.FileProvider"
    android:authorities="com.myfileprovider"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/file_provider_paths" />
</provider>

second, define your file paths in a separate XML file, I called it "file_provider_paths.xml"

<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="share" path="/" />
</paths>

you can find the complete explanation in this documentation page

after you have set up your file provider in XML, this is the code to share the image file:

Intent shareIntent = new Intent(Intent.ACTION_SEND);
shareIntent.setType("image/*");
Uri fileUri = FileProvider.getUriForFile(mContext, "com.myfileprovider", new File(mFilename));
shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
shareIntent.putExtra(Intent.EXTRA_STREAM, fileUri);
mContext.startActivity(Intent.createChooser(shareIntent, mChooserTitle));

Thank you very much for posting this - it helped me a great deal and works perfectly now. They only thing I had to work out was getting the path correct to the file. — ZipNFC, Nov 08 '17 at 11:04
String filename=mCSVname.getText().toString()+".csv"; File filelocation = new File(getExternalFilesDir (null), filename); Uri fileUri = FileProvider.getUriForFile(mContext, "com.myfileprovider", filelocation); — ZipNFC, Nov 08 '17 at 11:07

score 22 · Accepted Answer · answered Oct 06 '15 at 23:15

One limitation of the Android 6.0 runtime permission system is that there will be corner cases that cause problems. What you encountered is one: trying to share a file on external storage to an app that does not have the runtime permission checks in place for that particular UI path.

I say that this is a "corner case" because, for this bug in the receiving app to affect the user, the user cannot have previously used that app and granted the necessary permission. Either:

The user has never used that app before, yet it still trying to share content to it, or
The user revoked the permission via Settings, but did not realize that it would break this bit of functionality

Both of those are low probability events.

You, as the sender, have two main options:

Switch away from using file:// Uri values, in favor of a file-serving ContentProvider like FileProvider, so the permission is no longer needed, or
Just living with the corner case

@DanieleB: FWIW, I wrote up [a blog post](https://commonsware.com/blog/2015/10/07/runtime-permissions-files-action-send.html) about this. — CommonsWare, Oct 07 '15 at 13:44

score 2 · Answer 3 · answered Nov 10 '15 at 15:49

2

Alternatively, you don't need to have a ContentProvider / FileProvider . You can simply add the flag that grants read permission on the uri that is shared. Specifically, share.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); should do the trick.

answered Nov 10 '15 at 15:49

yrizk

394
2
8

score 0 · Answer 4 · answered Oct 11 '15 at 19:45

Another way I used to workaround this issue was to get content provider style URI using MediaScannerConnection right after you wrote your file to the public directory:

        MediaScannerConnection.scanFile(context, new String[] {imageFile.toString()}, yourMimeType, new OnScanCompletedListener() {
            @Override
            public void onScanCompleted(String path, Uri uri) {
                //uri = "content://" style URI that is safe to attach to share intent
            }
        });

This may be a shorter solution for your needs.

Android 6: cannot share files anymore?

4 Answers4

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