firebase_messaging: ^4.0.0+4 不起作用

Question

错误：-

Java.lang.NullPointerException： Try to invoke virtual method 'java.lang.String com.google.firebase.iid.FirebaseInstanceId.getToken((' on a null 对象引用

主构建.gradle

依赖关系 { 类路径 'com.android.tools.build：gradle：3.3.1' 类路径 'com.google.gms：google-services：4.0.1' }

App Level build.gradle

依赖关系 { test实现'junit：junit：4.12' androidTestImplementation 'com.android.support.test：runner：1.0.2' androidTestImplementation 'com.android.support.test.espresso：espresso-core：3.0.2' 实现 'com.google.firebase：firebase-core：16.0.1' } apply plugin： 'com.google.gms.google-services'

Adroid.manifest.xml

<activity android:name=".MainActivity" android:launchMode="singleTop" android:theme="@style/LaunchTheme" android:largeHeap="true" android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode" android:hardwareAccelerated="true" android:windowSoftInputMode="adjustResize">
    <!-- This keeps the window background of the activity showing
    until Flutter renders its first frame. It can be removed if
    there is no splash screen (such as the default splash screen
    defined in @style/LaunchTheme). -->
    <meta-data android:name="io.flutter.app.android.SplashScreenUntilFirstFrame" android:value="true" />
    <intent-filter>
        <action android:name="android.intent.action.MAIN"/>
        <category android:name="android.intent.category.LAUNCHER"/>
    </intent-filter>
</activity>

Answer 1

我发现位置插件和 FCM 插件的谷歌服务所需的版本的主要问题是不同的。

在应用级别 build.gradle 文件位于最底部

 dependencies {
        testImplementation 'junit:junit:4.12'
        androidTestImplementation 'com.android.support.test:runner:1.0.2'
        androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
        implementation 'com.google.firebase:firebase-core:16.0.1' } 
apply plugin: 'com.google.gms.google-services' com.google.gms.googleservices.GoogleServicesPlugin.config.disableVersionCheck
    = true