吸气剂'；代币'；使用facebook登录名在空firebase auth上调用-flatter

我正在尝试使用facebook登录Firebase

我正在使用firebaseauth:0.7.0和Flatter\u facebook\u登录：

以下是我的facebook登录功能：

  startFacebookLogin() async {
    var facebookLogin = FacebookLogin();
    var result = await facebookLogin
        .logInWithReadPermissions(['email', 'public_profile']);
    FacebookAccessToken myToken = result.accessToken;
    AuthCredential credential =
        FacebookAuthProvider.getCredential(accessToken: myToken.token);
    FirebaseUser firebaseUser =
        await FirebaseAuth.instance.signInWithCredential(credential);
    createProfile(user);
  }

这里我得到了一个错误：

E/flutter (19097): [ERROR:flutter/shell/common/shell.cc(186)] Dart Error: Unhandled exception:
E/flutter (19097): NoSuchMethodError: The getter 'token' was called on null.
E/flutter (19097): Receiver: null
E/flutter (19097): Tried calling: token
E/flutter (19097): #0      Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
E/flutter (19097): #1      _SignUpFirst.startFacebookLogin (package:tripmate/pages/signup_first.dart:40:65)
E/flutter (19097): <asynchronous suspension>
E/flutter (19097): #2      _SignUpFirst.build.<anonymous closure> (package:tripmate/pages/signup_first.dart:254:27)
E/flutter (19097): #3      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:507:14)
E/flutter (19097): #4      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:562:30)
E/flutter (19097): #5      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (19097): #6      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:242:9)
E/flutter (19097): #7      TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:175:7)
E/flutter (19097): #8      PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
E/flutter (19097): #9      PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
E/flutter (19097): #10     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
E/flutter (19097): #11     _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:180:19)
E/flutter (19097): #12     _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:158:22)
E/flutter (19097): #13     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:138:7)
E/flutter (19097): #14     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (19097): #15     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
E/flutter (19097): #16     _invoke1 (dart:ui/hooks.dart:173:13)
E/flutter (19097): #17     _dispatchPointerDataPacket (dart:ui/hooks.dart:127:5)
I/System.out(19097): (HTTPLog)-Static: isSBSettingEnabled false
I/System.out(19097): (HTTPLog)-Static: isSBSettingEnabled false

E/flatter（19097）：[错误：flatter/shell/common/shell.cc（186）]省道错误：未处理的异常：
E/flatter（19097）：NoSuchMethodError:对null调用了getter“token”。
E/颤振（19097）：接收器：空
E/Flatter（19097）：尝试呼叫：令牌
E/flatter（19097）：#0 Object.noSuchMethod（dart:core/runtime/libobject_patch.dart:50:5）
E/flatter（19097）：#1 SignUpFirst.startFacebookLogin（包：tripmate/pages/SignUpFirst.dart:40:65）
E/颤振（19097）：
E/flatter（19097）：#2#SignUpFirst.build。（套餐：tripmate/pages/signup_first.省道：254:27）
E/Flatter（19097）：#3(InkResponse Estate.)(handleTap)（包装：Flatter/src/material/InkWell.省道：507:14）
E/颤振（19097）：#4#InkResponseEstate.build。（包装：颤振/src/材料/墨水井。省道：562:30）
E/flatter（19097）：#5手势识别器.invokeCallback（包：flatter/src/signatures/recognizer.dart:102:24）
E/flatter（19097）：#6 TapGestureRecognitor.#检查（软件包：flatter/src/signatures/tap.dart:242:9）
E/flatter（19097）：#7 TapGestureRecognitor.handlePrimaryPointer（包：flatter/src/signatures/tap.dart:175:7）
E/Flatter（19097）：#8 PrimaryPointerGestureRecognizer.handleEvent（包：flatter/src/signatures/recognizer.dart:315:9）
E/flatter（19097）：#9点路由器。#调度（包：flatter/src/signatures/pointer#router。dart:73:12）
E/flatter（19097）：#10 PointerRouter.route（包：flatter/src/signatures/pointer_router.dart:101:11）
电子/颤振（19097）：#11#WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent（包：颤振/src/手势/binding.dart:180:19）
E/flatter（19097）：#12_WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent（包：flatter/src/signatures/binding.dart:158:22）
E/Flatter（19097）：#13#WidgetsFlutterBinding&BindingBase&GestureBinding.#handlePointerEvent（包装：Flatter/src/手势/绑定。省道：138:7）
电子/颤振（19097）：#14#WidgetsFlutterBinding&BindingBase&GestureBinding.#flushPointerEventQueue（包装：颤振/src/手势/binding.省道：101:7）
E/flatter（19097）：#15#WidgetsFlutterBinding&BindingBase&GestureBinding.#handlePointerDataPacket（packet:flatter/src/signatures/binding.dart:85:7）
E/颤振（19097）：#16_调用1（省道：ui/钩子。省道：173:13）
E/flatter（19097）：#17"调度指针数据包（dart:ui/hooks.dart:127:5）
I/System.out（19097）：（HTTPLog）-静态：isSBSettingEnabled false
I/System.out（19097）：（HTTPLog）-静态：isSBSettingEnabled false

---

任何人请帮我解决这个问题。

您应该在验证之前检查登录响应状态：

    var fbLogin = FacebookLogin();

    var result =
        await fbLogin.logInWithReadPermissions(['email', 'public_profile']);

    if (result.status == FacebookLoginStatus.loggedIn) {
      FacebookAccessToken myToken = result.accessToken;
      AuthCredential credential =
          FacebookAuthProvider.getCredential(accessToken: myToken.token);

      var user = await FirebaseAuth.instance.signInWithCredential(credential);
    }

另外，尝试将

firebase\u auth

更新为最新版本（目前为0.8.1+4）