HarmonyOS 鸿蒙Next中如何判断应用在前台还是后台

HarmonyOS 鸿蒙Next中如何判断应用在前台还是后台 https://developer.huawei.com/consumer/cn/doc/harmonyos-faqs/faqs-ability-101

• 方案一：通过窗口的on(‘windowStageEvent’)接口，开启 WindowStage 生命周期变化的监听，获取当前的生命周期状态。

代码示例:

// EntryAbility.ets
onWindowStageCreate(windowStage: window.WindowStage): void {
  // Main window is created, set main page for this ability
  hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');
  try {
    windowStage.on('windowStageEvent', (data) => {
      if (data === window.WindowStageEventType.SHOWN) {
        hilog.info(0x0000, 'testTag', '%{public}s', 'window stage is shown');
      } else if (data === window.WindowStageEventType.HIDDEN) {
        hilog.info(0x0000, 'testTag', '%{public}s', 'window stage is hidden');
      }
    });
  } catch (err) {
    hilog.error(0x0000, 'testTag', '%{public}s', 'Failed to enable the listener for ' +
      'window stage event changes. Cause:' + JSON.stringify(err));
  }
  windowStage.loadContent('pages/Index', (err, data) => {
    if (err.code) {
      hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
      return;
    }
    hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
  });
}

• 方案二：通过ApplicationContext的getRunningProcessInformation()方法获取进程信息，其中包含当前进程运行状态，可以判断是否处于前台。