HarmonyOS LiveEventBus 无法获取this

可以参考以下demo：

import { LiveEventBus } from '@ohos/liveeventbus';
import { MState } from '@ohos/liveeventbus';
import { Lifecycle } from '@ohos/liveeventbus';

const KEY_TEST_CLOSE_ALL_PAGE = "key_test_close_all_page";

@Entry({ routeName: "EditorPage" })
@Component
export struct EditorPage {
  @State message: string = 'Hello World';
  private mLifecycle?: Lifecycle;

  getLifecycle(): Lifecycle {
    if (this.mLifecycle) {
      return this.mLifecycle
    }
    return new Lifecycle(MState.STARTED)
  }

  aboutToAppear() {
    //创建生命周期感知对象
    this.mLifecycle = new Lifecycle(MState.STARTED)
    //订阅消息
    LiveEventBus
      .get<boolean>(KEY_TEST_CLOSE_ALL_PAGE)
      .observe(this, {
        onChanged: (b: boolean) => {
          this.message
        }
      });
  }

  build() {
    Column() {
    }
    .width('100%')
    .height('100%')
  }
}