在Flutter App中直接使用pigeon与原生平台通信

区别

在App中直接使用pigeon，与在插件中使用pigeon的步骤基本相同，唯一有区别的是，在原生层注册插件的代码不一样。

Android：

class MainActivity : FlutterActivity() {
  override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
    super.configureFlutterEngine(flutterEngine)
    HelloHostApi.setUp(flutterEngine.dartExecutor.binaryMessenger, api) 
  }

  private val api = object : HelloHostApi { 
  } 
}

iOS：

@main
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller : FlutterViewController = window?.rootViewController as! FlutterViewController 
    let api = AdServiceHostApiImpl() 
    AdServiceHostApiSetup.setUp(binaryMessenger: controller.binaryMessenger, api: api) 

    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
   
  private class HelloHostApiImpl : HelloHostApi{ 
  } 
}