I'm using Facebook Connect for iOS to post a picture, taken in an app, to facebook wall, possible using the local file URL, according to another post: adding photo on facebook wall
The URL appears to be pointing somewhere valid, but the picture doesn't show up. Verified that it does work with a web link. Anyone have an idea why this isn't working for local files? Would I need permissions beyond regular wall posts?
Help!
According to facebook, any image posted to a stream has to be web accessible, so what I wanted to do just isn't possible. The only way to get this to work is to upload the picture somewhere first, then use that URL.
If you want to get URL it's better to use ALAssetsLibrary method: writeImageToSavedPhotosAlbum:orientation:completionBlock:
It returns the a saved image URL in its callback block: ALAssetsLibraryWriteImageCompletionBlock. Should note that it's only available from iOS 4.0
来源：https://stackoverflow.com/questions/5137285/posting-picture-from-iphone-to-facebook-wall