Android Attaching a file to GMAIL - Can't attach empty file

Question

I had a program that would always attach the same file to GMAIL (Compose > Attach File > Open From > "MyProgram"). It would always select the same file.

What it was doing was:

String path = Environment.getExternalStorageDirectory() + "/file.3gp";
File f = new File(path);
Uri data = Uri.fromFile(f);
Intent i = new Intent();
i.setData(data);
setResult(Activity.RESULT_OK, i);
finish();

This was working fine until Android 6.0. Now, I receive the following error when trying to use it:

Can't attach empty file

Astro File Sharing is giving me the same error (can be an old build).

However, I installed ES File Explorer, and when I do the same routine, and select the file, I receive a Dialog which says:

Pick up file as

• Normal Android Way (For MMS,Gmail,...)
• File Way (Try this if above fails)

The "File Way" will fail as my program does. The "Normal Android Way" will work fine.

Does anyone have any idea on what it does, so I can replicate?

Thanks in advance!

OBS: Already tried the putExtra(STREAM, path) a lot of times, but without success.

Answer 1

Ok, got it to work now, after a lot of research and intercepting some Intents.

What I had to do was change the file:/// to content://.

I did this following this information from Android: https://developer.android.com/reference/android/support/v4/content/FileProvider.html

The only major change was that I used a hard-coded path to /sdcard/file.ext. Also, the line

getUriForFile(getContext(), "com.mydomain.fileprovider", newFile);

was changed to

Uri contentUri = FileProvider.getUriForFile(this, "com.mydomain.fileprovider", newFile);

Also had to include:

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
i.setData(contentUri);

I do not really understand why I had to change from File to Content, but after this, the file is now being attached again! See the link if you face this issue, and don't forget about the new .xml that needs to be created.