File.listfiles Returns Null When It Shouldn't

I am trying to get list of files existing in the Phone Pictures folder (internal storage, no SDCard inserted) using this: File file = Environment.getExternalStoragePublicDirectory

Solution 1:

If you are targeting Android SDK >=23 you need to take permission at run-time.

https://developer.android.com/training/permissions/requesting.html

Solution 2:

It returns null as Environment.getExternalStoragePublicDirectory will/is supposed to handle files from external storage like SD card..as you are stating no sd card is inserted

Solution 3:

As Abhishek Aryan suggested, I am using Android SDK >=23 so I had to obtain permissions using code:

boolean grantedAll = ContextCompat.checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
if (!grantedAll)
   {
     ActivityCompat.requestPermissions(thisActivity,
            newString[]{Manifest.permission.READ_EXTERNAL_STORAGE},
            REQUEST_PERMISSIONS);
   }