Android 6: cannot share files anymore?

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));

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:

1. Switch away from using file:// Uri values, in favor of a file-serving ContentProvider like FileProvider, so the permission is no longer needed, or

2. Just living with the corner case

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.