ios - 为什么 Swift Firebase auth() 响应晚？

Question

为什么 auth() 函数响应迟了？当 status 返回时，它总是返回函数开头定义的值。有没有办法用函数调用 auth() createUser？

func register(email: String, password: String) -> Dictionary<String, Any> {
    var status = ["stat": false] as Dictionary<String, Any>
    let handle = Auth.auth().createUser(withEmail: email, password: password) { (result, error) in
        if error != nil {
            status["stat"] = false
            status["statement"] = error!.localizedDescription as String
        } else {
            status["stat"] = true
        }
    }
    return status
}

The handle function returns before the end of the register function.

Answer 1

createUser 是一个异步方法，您可以延迟返回值直到createUser 完成，但这不是处理异步方法的最佳方式。

如果您为原始方法提供一个完成 block ，例如:

func register(email: String, password: String, completion: @escaping(([String: Any]) -> Void)) {
    var status: [String: Any] = ["stat": false]
    let handle = Auth.auth().createUser(withEmail: email, password: password) { (result, error) in
        if error != nil {
            status["stat"] = false
            status["statement"] = error!.localizedDescription as String
        } else {
            status["stat"] = true
        }

        completion(status)
    }
}

然后在任何其他地方，您可以确定 createUser 已完成其过程:

register(email: "email", password: "password") { status in
    // Now it's ready.
    print(status)
}