How can I launch facebook messenger with to enable user to user chat

问题

Users log into my app through the facebook sdk. If one user clicks on another user I'd like to enable them to chat via facebook messenger. I can launch messenger from my app, but is there a way to launch into the chat screen with a specific user.

回答1:

You can open a conversation in Messenger with deep links:

• http://m.me/{user_name} <- this is official link for Messenger. You'll need to ask user for his Messenger's username.
• fb-messenger://user/{user_id} <- this link is not documented, so it can break any time (Deep linking). user_id probably is the Facebook User Id, so it will be easier to obtain, however you'll need to ask for user_profile permission to get user id (Messenger Permissions)

来源：https://stackoverflow.com/questions/47255784/how-can-i-launch-facebook-messenger-with-to-enable-user-to-user-chat