Firebase: How to get User.uid?

问题

I'm using Firebaseauth to manage users and data for my iOS app. The users can log in, and their userinfo is stored correct in the database. But when I try to get the users to write to the database in a different viewController, using this string:

self.ref.child("users").child(user.uid).setValue(["username": username])

The thrown error is

Type user has no member .uid

That makes sense I guess, since I haven't created the variable. But I can't figure out how to declare it?

回答1:

This is how to get users uid:

let userID = Auth.auth().currentUser!.uid

回答2:

You might want to use a guard, as a force unwrap might break your app if a user isn’t signed in.

guard let userID = Auth.auth().currentUser?.uid else { return }

回答3:

FIRAuth has actually been renamed to Auth. So, as per the latest changes, it will be

let userID = Auth.auth().currentUser!.uid

Edit.

As pointed out in comments, A force unwrap may crash the app.

guard let userID = Auth.auth().currentUser?.uid else { return }

来源：https://stackoverflow.com/questions/44391706/firebase-how-to-get-user-uid