在flutter中创建Application.kt的最佳方式是什么

Question

My Application.kt文件如下。无法找到更改插件注册回调和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，我得到了这种类型的错误

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

试试这个，

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 Messaging。您可以看到下面的代码以更好地理解：

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，即FirebaseCloudMessagingPluginRegistrant.kt，并在其中放入以下代码：

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
}
}