我把项目gms:google_services降级为 类路径的com.google.gms:谷歌服务:4.0.1 这对我很管用。

google-services:4.1.0似乎有一个问题。要么降级为

classpath 'com.google.gms:google-services:4.0.0'

或将其升级为

classpath 'com.google.gms:google-services:4.2.0'

dependencies {
    classpath 'com.android.tools.build:gradle:3.3.0-alpha08'
    classpath 'com.google.gms:google-services:4.2.0'
    /*classpath 'com.google.gms:google-services:4.1.0' <-- this was the problem */
}

希望能有所帮助

发生的原因这里是com.google。gms:谷歌服务版本。当我使用4.1.0时，我遇到了同样的错误。然后我把版本降级。 之前

classpath 'com.android.tools.build:gradle:3.3.0'
classpath 'com.google.gms:google-services:4.1.0'

后

classpath 'com.android.tools.build:gradle:3.3.0'
classpath 'com.google.gms:google-services:3.2.0'

希望它能解决这个错误。

我们必须在应用程序类的onCreate函数中初始化Firebase。

 package com.rocks.music.videoplayer;

 import android.app.Application;
 import android.content.Context;

 import com.google.firebase.FirebaseApp;


/**
* Created by ashish123 on 22/8/15.
  */
 public class MyApplication extends Application {

private static MyApplication mInstance;

@Override
public void onCreate() {
    super.onCreate();
    mInstance = this;
    try {
        FirebaseApp.initializeApp(this);
    }
    catch (Exception e) {
    }
}

public static Context getInstance() {
    return mInstance;
}

}

清单文件中的代码:-

  <application
    android:name="com.rocks.music.videoplayer.MyApplication"
    android:allowBackup="true"
    android:icon="@drawable/app_icon"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

我猜google-services和firebase版本之间存在兼容性问题。

我在项目的构建中进行了更改。Gradle文件，依赖项

类路径'com.google.gms:google-services:4.1.0'到4.2.0

然后更新模块的构建。Gradle依赖于:

实现“com.google.firebase: firebase-database: 16.0.6”

实现“com.google.firebase: firebase-core: 16.0.7”

一切都像一个魅力，不需要键入FirebaseApp.initializeApp(这个);

首先你需要添加com.google.gms:google-services:x.x。X在根级别build.gradle

buildscript {
repositories {
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:2.3.1'
    classpath 'com.google.gms:google-services:3.0.0'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}

}

之后，你需要应用plugin: 'com.google.gms。Google-services在app/build.gradle

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support:design:25.3.1'
compile 'com.android.support:cardview-v7:25.3.1'

compile 'com.google.android.gms:play-services-gcm:9.8.0'
compile 'com.google.android.gms:play-services-maps:9.8.0'
compile 'com.google.android.gms:play-services-location:9.8.0'
compile 'com.google.firebase:firebase-messaging:9.8.0'
testCompile 'junit:junit:4.12'
}


apply plugin: 'com.google.gms.google-services'

如果你仍然有问题，那么你需要补充

FirebaseApp.initializeApp(this);

就在你打电话之前

FirebaseInstanceId.getInstance().getToken();