firebase - 由于 null 检查器问题，无法运行颤振移动应用程序

Question

我正在尝试将 firebase 连接到我的颤振应用程序。作为 Web 应用程序运行时，所有功能都运行良好。但是当我尝试运行移动应用程序时，该应用程序没有运行并在终端中显示如下错误消息。

E/flutter ( 4635): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: Null check operator used on a null value
E/flutter ( 4635): #0      MethodChannel.binaryMessenger
package:flutter/…/services/platform_channel.dart:142
E/flutter ( 4635): #1      MethodChannel._invokeMethod
package:flutter/…/services/platform_channel.dart:148
E/flutter ( 4635): #2      MethodChannel.invokeMethod
package:flutter/…/services/platform_channel.dart:331
E/flutter ( 4635): #3      MethodChannel.invokeListMethod
package:flutter/…/services/platform_channel.dart:344

以下是我正在使用的依赖项：

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  firebase_core: "0.5.1"
  firebase_auth: "0.18.2"
  cloud_firestore: "0.14.2"

下面是我的 main.dart 文件

Future<void> main() async {
  await Firebase.initializeApp();
  runApp(new MaterialApp(
    home: Login(),
  ));
}

在运行 Flutter 频道时：

PS C:\Users\hp\Documents\firebase\blog_app> flutter channel
Flutter channels:
  master
  dev
  beta
* stable

Answer 1

如下更改您的 pubspec.yaml。

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  firebase_core: ^1.3.0
  firebase_auth: ^1.4.1
  cloud_firestore: ^2.2.2

并flutter put get在终端中运行

然后运行flutter channel stable，flutter upgrade并flutter clean在终端