File sharing / send file in another app (“open in” in iOS)

Question

my app make a simple file called log.txt

the URL of this file (viewed in xcode) is file://localhost/var/mobile/Applications/NUMBER OF THE APPLICATION/Documents/

Answer 1

Here is how it works for me :

I just put the declaration "UIDocumentInteractionController *documentController" in the .h file and it works !

I really don't know why, but ....