监听自身应用是否处于前后台状态的变化可参考:https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-inner-application-applicationcontext-V5\#applicationcontextontype-applicationstatechange-callback-applicationstatechangecallback10
监听自身应用是否处于前后台状态的变化可参考:https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-inner-application-applicationcontext-V5\#applicationcontextontype-applicationstatechange-callback-applicationstatechangecallback10