Android Question Samsung j7 pro

[rogel a. tolentino]

I develop a simple program and succesfully done the reading and writing a text file in DirRootExternal of a MyPhone device (Android version 7.0). But when I applied the same program at Samsung j 7 pro it cannot access.
adb push reader.txt /sdcard/reader.txt is succeful and i can view said file at the root of phone memory.
What do you thibk is wrong in Samsung j7 pro?

 

[DonManfred]

I don´t think the problem is in j7 Pro but more i expect the problem in your code.
Upload a project which shows the issue