.NET 桌面应用程序不支持接收 FCM 通知.该平台没有FCM SDK，有线协议没有文档.

There is no support for receiving FCM notifications in a .NET desktop application. There is no FCM SDK for the platform, and the wire protocol is undocumented.

支持 在 Android 或 iOS 上的 Xamarin 应用上接收 FCM 通知，但这似乎不是您所追求的.

There is support for receiving FCM notifications on a Xamarin app on Android or iOS, but that doesn't seem to be what you're after.