Flutter Android Embedding V1 和 V2 有什么区别

1. Ffltter发布了新版本的Android Embedding.这是负责将Ffltter集成到Android应用程序中的Android代码.它包括像FlutterActivity、FlutterFragment、FlutterView和FlutterEngine这样的类.v2 Android嵌入包括对标准Android生命周期事件的支持，以及将Flutter 执行与Android UI分离，这是v1 Android嵌入所缺少的.在v2Android嵌入的开发过程中，很明显，现有的Flutter 插件API不足以处理v2Android嵌入的新功能.需要一个新的Android插件API.

2. 在旧的v1Android嵌入中，所有插件都是在Android应用程序的一开始就初始化和配置的，而且只有一次Flutter 体验.在v2嵌入中，我们不假设插件何时初始化，每个FlutterEngine插件必须初始化一次.因此，所有用于安卓的Ffltter插件现在都必须支持实例化，而不是静电初始化，并且它们必须支持附加到FlutterEngine和从FlutterEngine分离.以下代码示例演示了旧的v1插件初始化实现和新的v2插件初始化过程之间的区别.

旧插件初始化

class MyOldPlugin {
  public static void registerWith(PluginRegistrar registrar) {
    // Obtain any references that the plugin requires from the 
    // registrar.
    //
    // This plugin is now considered "initialized" and "attached" 
    // to a Flutter experience.
  }
}

新插件初始化

class MyNewPlugin implements FlutterPlugin {
  public MyNewPlugin() {
    // All Android plugin classes must support a no-args 
    // constructor. A no-arg constructor is provided by 
    // default without declaring one, but we include it here for 
    // clarity.
    //
    // At this point your plugin is instantiated, but it 
    // isn't attached to any Flutter experience. You should not 
    // attempt to do any work here that is related to obtaining 
    // resources or manipulating Flutter.
  }
  @override
  public void onAttachedToFlutterEngine(FlutterPluginBinding binding) {
    // Your plugin is now attached to a Flutter experience 
    // represented by the given FlutterEngine. 
    //
    // You can obtain the associated FlutterEngine with
    // binding.getFlutterEngine()
    //
    // You can obtain a BinaryMessenger with 
    // binding.getBinaryMessenger()
    // 
    // You can obtain the Application context with
    // binding.getApplicationContext()
    //
    // You cannot access an Activity here because this 
    // FlutterEngine is not necessarily displayed within an 
    // Activity. See the ActivityAware interface for more info.
  }
  @override
  public void onDetachedFromFlutterEngine(FlutterPluginBinding binding) {
    // Your plugin is no longer attached to a Flutter experience. 
    // You need to clean up any resources and references that you 
    // established in onAttachedToFlutterEngine().
  }
}

此外，您的插件不能依赖于onAttachedToFlutterEngine()中的活动引用.仅仅因为您的插件附加到Flutter 体验，并不意味着Flutter 体验将在活动中展示.This is one of the most significant differences between the old and new plugin APIs美元.在旧的v1插件API中，插件作者可以依赖于活动立即和永久可用.这已经不是真的了.

有关更多信息，请参见https://medium.com/flutter/modern-flutter-plugin-development-4c3ee015cf5a