在 flutter 中创建 Application.kt 的最佳方法是什么

Question

我的 Application.kt 文件是这样的。 找不到更改PluginRegistrantCallback和FlutterFirebaseMessagingService的方法

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService


class Application : FlutterApplication(), PluginRegistrantCallback {
    override fun onCreate() {
        super.onCreate()
        FlutterFirebaseMessagingService.setPluginRegistrant(this)
    }

    override fun registerWith(registry: PluginRegistry?) {
        io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.registerWith(
                registry?.registrarFor(
                        "io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
    }
}

ext.kotlin_version = '1.5.10' 当我构建项目时出现这种类型错误

e: /-/Application.kt: (6, 27): Unresolved reference: firebasemessaging
e: /-/Application.kt: (12, 9): Unresolved reference: FlutterFirebaseMessagingService
e: /-/Application.kt: (16, 28): Unresolved reference: firebasemessaging

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compileDebugKotlin'.
> Compilation error. See log for more details

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 13s
Exception: Gradle task assembleDebug failed with exit code 1

Answer 1

尝试这个，

package your_package_name

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry

import io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin

class Application() : FlutterApplication(), PluginRegistry.PluginRegistrantCallback {
  override fun registerWith(registry: PluginRegistry?) {
      val key: String? = FlutterFirebaseMessagingPlugin::class.java.canonicalName
      if (!registry?.hasPlugin(key)!!) {
          FlutterFirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin"));
        }
    }
}

Answer 2

您可以使用FirebaseCloudMessagingPluginRegistrant注册 Firebase 消息传递。 您可以查看以下代码以更好地理解：

package <package_name>

import io.flutter.app.FlutterApplication
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.GeneratedPluginRegistrant
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin


class Application : FlutterApplication(), PluginRegistrantCallback {
    override fun onCreate() {
        super.onCreate()
        FlutterFirebaseMessagingService.setPluginRegistrant(this)
    }

    override fun registerWith(registry: PluginRegistry?) {
        FirebaseCloudMessagingPluginRegistrant.registerWith(registry)
    }
}

您还需要创建另一个文件FirebaseCloudMessagingPluginRegistrant.kt并将以下代码放入其中：

package <package_name>

import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin

object FirebaseCloudMessagingPluginRegistrant {
    fun registerWith(registry: PluginRegistry?) {
        if (alreadyRegisteredWith(registry)) {
            return
        }
            FirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"))
    }

    private fun alreadyRegisteredWith(registry: PluginRegistry?): Boolean {
        val key: String? = FirebaseCloudMessagingPluginRegistrant::class.java.canonicalName
        if (registry?.hasPlugin(key)!!) {
            return true
        }
        registry.registrarFor(key)
        return false
    }
}