Well, from the comments, it looks like what you want to post on the user's wall. Below is a method that is available in the FB SDK that invokes the sharing dialog in your application and supports pre-filled text
[FBDialogs presentOSIntegratedShareDialogModallyFrom:self initialText:@"Initial text" image:nil url:nil handler:nil];
Example with pre-filled text:
What type of dialogue do you open? (Sounds like a send dialog if you want to send a Facebook message.)
I do not think that you can even send a message directly to a user from iOS. When doing the following, I get the error message "This dialog is not available on this device"
[FBWebDialogs presentDialogModallyWithSession:nil dialog:@"send" parameters ...
The iOS FB SDK WebDialog Link shows the following methods:
+ presentRequestsDialogModallyWithSession:message:title:parameters:handler: + presentRequestsDialogModallyWithSession:message:title:parameters:handler:friendCache:
They seem to support pre-populating a message field. They only support apprequests (not messages) and even the attachment message is a bit unknown (all I saw when testing was “User wants to try the application”, not the actual line I installed).
The javascript API (which could possibly be raised in webview?) Does not have a parameter for setting the message, probably because Send the online documentation :
Facebook messaging is a channel for communication between people, not applications for sending messages or encouraging people to spam friends.
If you just want to post a post / share, you can use a share sheet that looks to support the initial post:
[FBNativeDialogs presentShareDialogModallyFrom:self initialText:@"My text to share" ...