Android - Sending TXT File as Attachment to Email Fails (“Couldn't send attachment”)

问题

I am trying to get my Android app to send an e-mail with a file attached, and I'm starting out with a .txt file, since those are simple.

So far I have this (taking place inside a Fragment):

//Send the email
Intent mailIntent = new Intent(Intent.ACTION_SEND);
mailIntent.setType("text/Message");
mailIntent.putExtra(Intent.EXTRA_EMAIL  , new String[]{address});
mailIntent.putExtra(Intent.EXTRA_SUBJECT, "Test Email");
mailIntent.putExtra(Intent.EXTRA_TEXT   , "Hi!  This is a test!");

//Deal with the attached report
String FileName = "report.txt";
Calculator.generateReport(getActivity().getApplicationContext(), FileName);
//It will be called "report.txt"
File attachment = getActivity().getApplicationContext().getFileStreamPath(FileName);
if (!attachment.exists() || !attachment.canRead()) {
    Toast.makeText(getActivity().getApplicationContext(), 
                   "Attachment Error", 
                   Toast.LENGTH_SHORT).show();
    System.out.println("ATTACHMENT ERROR");
}
else
{
    Uri uri = Uri.fromFile(attachment);
    mailIntent.putExtra(Intent.EXTRA_STREAM, uri);
}

//Send, if valid!
try {
   startActivity(Intent.createChooser(mailIntent, "Send mail..."));
} catch (android.content.ActivityNotFoundException ex) {
    Toast.makeText(getActivity().getApplicationContext(), 
               "There are no email clients installed.", 
               Toast.LENGTH_SHORT).show();
}

Unfortunately, that doesn't seem to work. Now I know the file exists; if I insert the appropriate code after generateReport(), I can find and access the file and read its contents. It is there, and I have the right name.

When I am given the option of choosing an email client, I pick Gmail and see that there is indeed a report.txt file attached to the email. When I send the email, though, I get a notification stating "Couldn't send attachment", and the email arrives without anything attached.

I should note that I have tried other intent types as well, such as text/plain and message/rfc822, to no avail.

Any ideas on what I might be doing wrong?

回答1:

If you have saved the file as being private to the app, the app can see if fine but the external email client will not be able to see it.

You'll need to write it out to external storage, or make it public.

Use http://developer.android.com/reference/android/content/Context.html#MODE_WORLD_READABLE or http://developer.android.com/guide/topics/data/data-storage.html

回答2:

https://stackoverflow.com/a/18548685/293280

The above SO answer for a really good walkthrough of copying the file, attaching it to the email, sending the email and, finally, deleting the copied file.

来源：https://stackoverflow.com/questions/15961409/android-sending-txt-file-as-attachment-to-email-fails-couldnt-send-attachme