根据@ZakTaccardi的回答，并且假设您不想在两个版本中都使用一个项目，请将此添加到构建的末尾。gradle文件:

def appModuleRootFolder = '.'
def srcDir = 'src'
def googleServicesJson = 'google-services.json'

task switchToStaging(type: Copy) {
    outputs.upToDateWhen { false }
    def flavor = 'staging'
    description = "Switches to $flavor $googleServicesJson"
    delete "$appModuleRootFolder/$googleServicesJson"
    from "${srcDir}/$flavor/"
    include "$googleServicesJson"
    into "$appModuleRootFolder"
}

task switchToProduction(type: Copy) {
    outputs.upToDateWhen { false }
    def flavor = 'production'
    description = "Switches to $flavor $googleServicesJson"
    from "${srcDir}/$flavor/"
    include "$googleServicesJson"
    into "$appModuleRootFolder"
}

afterEvaluate {
    processStagingDebugGoogleServices.dependsOn switchToStaging
    processStagingReleaseGoogleServices.dependsOn switchToStaging
    processProductionDebugGoogleServices.dependsOn switchToProduction
    processProductionReleaseGoogleServices.dependsOn switchToProduction
}

你需要src/staging/google-services文件。Json和src/production/google-services.json。替换您所使用的风味名称。

我正在使用谷歌服务。json文件，从这里创建:https://developers.google.com/mobile/add?platform=android&cntapi=gcm&cnturl=https:%2F%2Fdevelopers.google.com%2Fcloud-messaging%2Fandroid%2Fclient&cntlbl=Continue%20Adding%20GCM%20Support&%3Fconfigured%3Dtrue

在json结构中，有一个称为客户机的json数组。如果你有多种口味，只需在这里添加不同的属性。

{
  "project_info": {
    "project_id": "PRODJECT-ID",
    "project_number": "PROJECT-NUMBER",
    "name": "APPLICATION-NAME"
  },
  "client": [
    {
      "client_info": {
        "mobilesdk_app_id": "1:PROJECT-NUMBER:android:HASH-FOR-FLAVOR1",
        "client_id": "android:PACKAGE-NAME-1",
        "client_type": 1,
        "android_client_info": {
          "package_name": "PACKAGE-NAME-1"
        }
      },
      "oauth_client": [],
      "api_key": [],
      "services": {
        "analytics_service": {
          "status": 1
        },
        "cloud_messaging_service": {
          "status": 2,
          "apns_config": []
        },
        "appinvite_service": {
          "status": 1,
          "other_platform_oauth_client": []
        },
        "google_signin_service": {
          "status": 1
        },
        "ads_service": {
          "status": 1
        }
      }
    },
    {
      "client_info": {
        "mobilesdk_app_id": "1:PROJECT-NUMBER:android:HASH-FOR-FLAVOR2",
        "client_id": "android:PACKAGE-NAME-2",
        "client_type": 1,
        "android_client_info": {
          "package_name": "PACKAGE-NAME-2"
        }
      },
      "oauth_client": [],
      "api_key": [],
      "services": {
        "analytics_service": {
          "status": 1
        },
        "cloud_messaging_service": {
          "status": 2,
          "apns_config": []
        },
        "appinvite_service": {
          "status": 1,
          "other_platform_oauth_client": []
        },
        "google_signin_service": {
          "status": 1
        },
        "ads_service": {
          "status": 1
        }
      }
    }
  ],
  "client_info": [],
  "ARTIFACT_VERSION": "1"
}

在我的项目中，我使用相同的项目id，当我在上面的url中添加第二个package-name时，谷歌为我提供了一个包含json-data中的多个客户端的文件。

我发现google-services插件对于想要添加GCM的项目来说是非常无用的。它只生成以下文件，简单地将您的项目ID添加为字符串资源:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- Your API key would be on the following line -->
    <string name="gcm_defaultSenderId">111111111111</string>
</resources>

似乎只有在直接从Cloud Messaging for Android指南复制样例代码时才需要它。下面是示例行:

String token = instanceID.getToken(getString(R.string.gcm_defaultSenderId),              GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);

解决方案

如果您希望能够为不同的构建类型或产品风格切换API项目，您只需定义自己的常量，并在调用getToken() API时选择适当的常量。

private static final String SENDER_ID = "111111111111";
private static final String SANDBOX_SENDER_ID = "222222222222";

String token = instanceID.getToken(
        BuildConfig.DEBUG ? SENDER_ID : SANDBOX_SENDER_ID,
        GoogleCloudMessaging.INSTANCE_ID_SCOPE,
        null);

产品口味

上面的代码用于在调试和发布版本之间切换。对于产品类型，您可以在java源文件中定义不同的API键，并将这些文件放在相应的产品类型目录中。参考:Gradle Build variables

所以如果你想通过编程复制google的服务。Json文件从你的所有变体到你的根文件夹。当你切换到特定的变体时，这里有一个解决方案

android {
  applicationVariants.all { variant ->
    copy {
        println "Switches to $variant google-services.json"
        from "src/$variant"
        include "google-services.json"
        into "."
    }
  }
}

这种方法有一个警告，那就是你需要有谷歌服务。Json文件在你的每个变体文件夹这里是一个例子。

我目前在同一个应用程序包中使用两个GCM项目Id。我加入了谷歌服务。我的第一个GCM项目的json，但我从第一个切换到第二个只改变SENDER_ID:

    String token = instanceID.getToken(SENDER_ID,GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);

(在这一点上，我认为谷歌的服务。Json不是强制性的)

    ...
    gradle.taskGraph.beforeTask { Task task ->
        if (task.name ==~ /process.*GoogleServices/) {
            android.applicationVariants.all { variant ->
                if (task.name ==~ /(?i)process${variant.flavorName}(Debug|Release)GoogleServices/) {
                    copy {
                        from "src/tenants/${variant.flavorName}"
                        include 'google-services.json'
                        into '.'
                    }
                }
            }
        }
    }

    gradle.taskGraph.afterTask { Task task ->
        if (task.name ==~ /process.*GoogleServices/) {
            android.applicationVariants.all { variant ->
                if (task.name ==~ /(?i)process${variant.flavorName}(Debug|Release)GoogleServices/) {
                    delete fileTree(".").matching {
                        include 'google-services.json'
                    }
                }
            }
        }
    }