HarmonyOS SDK内后台模式监听

可以参考如下代码实现在page页面监听前后台切换：

import { window } from '@kit.ArkUI';
import { common } from '@kit.AbilityKit';

@Entry
@Component
struct Index {
  context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext;

  aboutToAppear(): void {
    window.getLastWindow(this.context).then((lastWindow) => {
      console.log("获取到到的当前页面的window：", lastWindow)
      lastWindow?.on('windowEvent', (data) => {
        console.info('lastWindow event happened. Event:' + JSON.stringify(data));
      });
    })
  }

  build() {
    Column() {
      Text("监听前后台切换")
    }.width("100%").height("100%").justifyContent(FlexAlign.Center)
  }
}

窗口监听对应官网文档链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-window-V5#onwindowevent10