I am developing an iOS app that uses the UIActivityViewController to share some text and a Url. In the Facebook and Twitter services it shows a thumbnail of the site located at the URL.
Unfortunately, the site in question does not look very good at all in the thumbnail. So currently the thumbnail has a negative value in the share dialog. I would either like to prevent the thumbnail from displaying, or supply my own image for the thumbnail. What is the best method to do this?
I would like to avoid having to create my own service and/or dialog.
I have tried adding an image to the item list, however that adds a bunch of services I don't want and adds the Image to the email action and adds the image to a photo album on facebook. The first problem I can get around by blacklisting actions I don't want. And I can make my own UIActivityItemProvider to stop the email problem. However, I have no idea how to prevent the facebook problem. (See How do I customize a UIActivityViewController to show a URL link when posting to facebook and twitter?).
Here is a screenshot of the facebook sharing dialog:
