iOS 11 added a new Files app for managing files. Is it possible to present an Open screen from my Xojo app to retrieve a file stored in the Files app?
I assume I can use the iOSSharingPanel to save a file out to the Files app.
Yes iOSSharingPanel will save a file to the Files app. Id love to know the answer to your first question as well. 
It should be possible with declares. On my list of things to add to iOSKit but time is limited lately.
This seems to be the thing we need: https://developer.apple.com/documentation/uikit/uidocumentbrowserviewcontroller
So then this “breaks the bonds” of the sandbox to some extent…if I understand that correctly?
As in an app (yours or others) can given permission to allow other apps to read (and write?) to their /Documents folder?
This would be equivilanent to Desktop Apps reading/writing to /ApplicationSupport/ I’d guess?
The Files system is separate from each individual app’s sandbox. So this is more akin to the photos browser which any app can call and, provided the user gives permission, is able to present a list of photos and retrieve a photo selected by the user. But instead of a list of photos, it’s a list of documents in the Files system.
that is why I used “”
It still allows (with permission) the ability to locate, read and write files that are inside another apps domain,
I was describing function not method… I can see uses for this of course, but I can also see possible issues created by “bad actors” that might seek out “public” document folders… but then not any more so than happens on a desktop I guess