ios - Swift - 从 facebook 登录中获取错误

Question

刚开始我已经看过很多例子，但似乎找不到解决方案。好吧，我以为我做到了，但它似乎不起作用。

我想做的是使用 Facebook 的 Firebase 身份验证登录方法，顺便说一句。我的问题是当 facebook 方法抛出电子邮件/凭据已存在的错误时，我想链接密码 auth 凭据和 facebook auth 凭据。我读了here我可以使用 error.email 但它没有给我访问 email.error 的选项。我可能遗漏了一些东西，我花了很多时间试图弄明白。

这是我的代码:

func signInFacebookUser() {
    let fbLoginManager = FBSDKLoginManager()
    fbLoginManager.logIn(withReadPermissions: ["public_profile", "email"], from: self) { (result, error) in
        if let error = error {
            self.errorMessagePopUp(title: "Failed to login", message: error)
            return
        }

        guard let accessToken = FBSDKAccessToken.current() else {
        print("Failed to get access token")
        return
   }

   let credential = FacebookAuthProvider.credential(withAccessToken: accessToken.tokenString)

   Auth.auth().signIn(with: credential, completion: { (user, error) in
        if let error = error {

        let errCode = AuthErrorCode(rawValue: error._code)!

        switch errCode {

              case .accountExistsWithDifferentCredential:
              // somehow obtain email right here.
              self.showSigninForm(attributes: self.attributes(), style: .light)
              return

             default:
             return
          }
       }

       self.performSegue(withIdentifier: "signInBtnPressed", sender: nil)
    })
  }
}

Answer 1

这适用于我的 Swift4

@objc func loginButtonClicked() {
    var alertController = UIAlertController()
    let loginManager = LoginManager()
    loginManager.logIn(readPermissions: [ReadPermission.email], >viewController: self, completion: {loginResult in
                    switch loginResult {
                    case .failed(let error):
                        print(error)
                    case .cancelled:
                        print("User cancelled login.")
                    case .success(_, _, let accessToken):
                        print(accessToken)

                    }

    })
}

 func getDataUser() {
        let request = GraphRequest(graphPath: "me?fields=first_name,last_name,email",
                                   parameters:[:],
                                   httpMethod: .GET)
        request.start { httpResponse, result in
            switch result {
            case .success(let response): do {
                print("Graph Request Succeeded: \(response)")
                let dicval = response.dictionaryValue
                let email = dicval?.keys
                print("Graph Request Succeeded: \(String(describing: email))")
                }
            case .failed(let error):
                print("Graph Request Failed: \(error)")
            }

        }
    }
}