尝试将创建的文本文件作为电子邮件附件发送 - 从默认文件夹中

I am trying something simple as creating a text file and then send it as attachment. While it works fine if I use the sdcard I don't know where to put it in the "standard data folder" so my app works actually for everyone without sdcard (and the file is somewhat invisible)I am trying something simple as creating a text