how to avoid logging users out when migrating from iOS Facebook 2.x -> 3.x
问题 Upgrading our Facebook iOS integration from the 2.x SDK to 3.x SDK automatically logs users out who were previously logged in, since the authentication credentials that we used to have to manually handle ourselves are now handled behind-the-scenes by the new SDK. Is there any way to force the 3.x SDK to authenticate using the access token and expiration date that we were previously manually storing, as a one-time authentication migration? Thanks in advance! 回答1: Finally figured it out. The