iPhone - Facebook post to a friend's wall

I am working on an application on facebook integration. I don't know how to post on a friends wall or 开发者_JAVA技巧if this is possible.

Or at least to send his friends a message.

Can anyone give me a clue?

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There's a similar related thread here about posting to facebook wall (unfortunately that was the case for the user him/herself only). I was thinking that you might be able to modify the graph path to use a friend's user_id instead of your own, in the fragment:-

...requestWithGraphPath:@"[user_id]/feed"...

Need to first test it out to verify this, but this seems like an option to me.