Document Interaction
If your application creates photos, videos, or audio notes and you’d like your users to share these media using WhatsApp, you can use the Document Interaction API to send your media to your WhatsApp contacts and groups.
WhatsApp Messenger can handle various types of media:
images of any type that conforms to public.image (for example, PNG and JPEG)
videos of any type that conforms to public.movie (for example, MPEG-4 video)
audio files (only MPEG-3, MPEG-4, AIFF, AIFF-C and Core Audio)
Alternatively, if you want to show only WhatsApp in the application list (instead of WhatsApp plus any other public/*-conforming apps) you can specify a file of one of the aforementioned types saved with the extension that is exclusive to WhatsApp:
images - «.wai» which is of type net.whatsapp.image
videos - «.wam» which is of type net.whatsapp.movie
audio files - «.waa» which is of type net.whatsapp.audio
When triggered, WhatsApp will immediately present the user with the contact/group picker screen. The media will be automatically sent to a selected contact/group.
See the Apple documentation articles: Previewing and Opening Files and the UIDocumentInteractionController Class Reference for more information.
For more details plz check this link:- http://www.whatsapp.com/faq/en/iphone/23559013
Sample code for sharing video:-
self.documentationInteractionController.UTI = @"net.whatsapp.movie";
self.documentationInteractionController = [UIDocumentInteractionController interactionControllerWithURL: fileURL];
self.documentationInteractionController.delegate = self;
[self.documentationInteractionController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];