Day23 Plugin 从零开始到上架 - ActivityAware 介绍

ActivityAware

如果插件需要与UI 进行互动，例如请求权限或更改Android UI ，那麽您就需要一些附加步骤来构建您的插件。您必须实现 ActivityAware，Flutter 提供了 ActivityAware 用於 Activity 的生命周期管理和获取

public class MyPlugin implements FlutterPlugin, ActivityAware {
  //...normal plugin behavior is hidden...

  @Override
  public void onAttachedToActivity(ActivityPluginBinding activityPluginBinding) {
    // TODO: your plugin is now attached to an Activity
  }

  @Override
  public void onDetachedFromActivityForConfigChanges() {
    // TODO: the Activity your plugin was attached to was
    // destroyed to change configuration.
    // This call will be followed by onReattachedToActivityForConfigChanges().
  }

  @Override
  public void onReattachedToActivityForConfigChanges(ActivityPluginBinding activityPluginBinding) {
    // TODO: your plugin is now attached to a new Activity
    // after a configuration change.
  }

  @Override
  public void onDetachedFromActivity() {
    // TODO: your plugin is no longer associated with an Activity.
    // Clean up references.
  }
}

onAttachedToEngine和onDetachedFromEngine 是FlutterPlugin的介面方法，是flutter新的载入Plugin 的方式，onAttachedToActivity和onDetachedFromActivity是ActivityAware的介面方法，主要是用於获取当前flutter 页面所处的Activity.

我们可以将Plugin 设计将MethodHandler 在 onAttachedToEngine 方法中被初始化和构建，在 onDetachedFromEngine 方法中释放；同时 Activity 相关的四个实现方法也提供了相应的操作逻辑