我正在使用Facebook进行首次身份验证。所以，我很困惑。实际上，我能够从Facebook身份验证中获取数据，但是当我尝试获取电子邮件地址时，却无法从数据中获取电子邮件地址。
我搜索了很多有关此问题的信息，但找不到实际的解决方案。
var facebookLogin = new FacebookLogin();
var result = await facebookLogin.logInWithReadPermissions(['email']);
switch (result.status) {
case FacebookLoginStatus.loggedIn:
final token = result.accessToken.token;
AuthCredential fbCredential = FacebookAuthProvider.getCredential(
accessToken: token);
FirebaseAuth.instance.signInWithCredential(fbCredential).then((
FirebaseUser user) {
assert(user.displayName!=null);
assert(!user.isAnonymous);
print("User"+user.toString());
print("Name"+user.displayName);
print("email"+user.email);
// do something...
});
break;
显示数据异常：
UserFirebaseUser({providerData: [{uid: 0**********, providerId: firebase,
displayName: G**** , photoUrl:
https://graph.facebook.com/1**********/picture}, {email: man*****@gmail.com,
uid: 105*********3, providerId: facebook.com, displayName: G****, photoUrl:
https://graph.facebook.com/18888***41023/picture}], providerId: firebase,
photoUrl: https://graph.facebook.com/105********3/picture, isAnonymous:
false, uid: 0x581JD7Iof*********Dm1, creationTimestamp: ********1117,
lastSignInTimestamp: 1564*******0, isEmailVerified: false, displayName:
G***})
I/flutter ( 3546): NameG*****a
E/flutter ( 3546): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: Invalid argument(s)
E/flutter ( 3546): #0 _StringBase.+ (dart:core-patch/string_patch.dart:260:57)
E/flutter ( 3546): #1 _MyAppState.facebookSignin.<anonymous closure> (package:flutter_app/Screens/LoginScreen.dart:143:24)
E/flutter ( 3546): #2 _rootRunUnary (dart:async/zone.dart:1132:38)
E/flutter ( 3546): #3 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
E/flutter ( 3546): #4 _FutureListener.handleValue (dart:async/future_impl.dart:126:18)
E/flutter ( 3546): #5 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:639:45)
E/flutter ( 3546): #6 Future._propagateToListeners (dart:async/future_impl.dart:668:32)
E/flutter ( 3546): #7 Future._complete (dart:async/future_impl.dart:473:7)
E/flutter ( 3546): #8 _SyncCompleter.complete (dart:async/future_impl.dart:51:12)
E/flutter ( 3546): #9 _AsyncAwaitCompleter.complete (dart:async-patch/async_patch.dart:28:18)
E/flutter ( 3546): #10 _completeOnAsyncReturn (dart:async-patch/async_patch.dart:294:13)
E/flutter ( 3546): #11 FirebaseAuth.signInWithCredential (package:firebase_auth/src/firebase_auth.dart)
E/flutter ( 3546): <asynchronous suspension>
E/flutter ( 3546): #12 _MyAppState.facebookSignin (package:flutter_app/Screens/LoginScreen.dart:137:31)
E/flutter ( 3546): <asynchronous suspension>
E/flutter ( 3546): #13 _MyAppState.build.<anonymous closure> (package:flutter_app/Screens/LoginScreen.dart:577:31)
E/flutter ( 3546): #14 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:511:14)
E/flutter ( 3546): #15 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:566:30)
E/flutter ( 3546): #16 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:166:24)
E/flutter ( 3546): #17 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:240:9)
E/flutter ( 3546): #18 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:177:9)
E/flutter ( 3546): #19 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:436:9)
E/flutter ( 3546): #20 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
E/flutter ( 3546): #21 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
E/flutter ( 3546): #22 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:221:19)
E/flutter ( 3546): #23 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:199:22)
E/flutter ( 3546): #24 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter ( 3546): #25 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter ( 3546): #26 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter ( 3546): #27 _rootRunUnary (dart:async/zone.dart:1136:13)
E/flutter ( 3546): #28 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
E/flutter ( 3546): #29 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
E/flutter ( 3546): #30 _invoke1 (dart:ui/hooks.dart:233:10)
E/flutter ( 3546): #31 _dispatchPointerDataPacket (dart:ui/hooks.dart:154:5)
E/flutter ( 3546):