I've tried a lot of method and I've read a lot of posts, without find a valid soluction.
Summing:
I try to use this https://github.com/18446744073709551615/android-file-chooser-dialog to choose a directory and use it. This code work perfectly with internal storage.
With this code: System.getenv("SECONDARY_STORAGE")
, on my Asus TF201 with JellyBean and with Lollipop, I have /storage/sdcard1
and I can use this with previus code and it works.
Now, the problem.
I've tried with this (and other similar solution): How can I get external SD card path for Android 4.0+? but on LG G3 with Android 6.0 I've /mnt/media_rw/9014-4EF8
and doesn't work with previous code.
How can I obtain the external sd path? I need only to read in sd. Or can I use /mnt/media_rw/9014-4EF8
?