如何更新时钟时间片段 [英] how to update fragment on clock time

问题描述

我正在尝试使用以下逻辑在时钟时间更新片段，例如8PM。不幸的是，它不会更新片段。任何帮助/参考将不胜感激。

I'm trying to update fragment on clock time, say for example 8PM, with below logic. Unfortunately, it doesn't update the fragment. Any help/reference would be appreciated.

我做了什么：

1. 在应用的应用程序类中注册了 AlarmManager ：

    alarmMgr = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent().setAction(AppConstants.INTENT_ACTION_UPDATE_DASHBOARD);
    alarmIntent = PendingIntent.getBroadcast(context, 0, intent, 0);

    // Set the alarm to start at Consulting start time
    Calendar calendar = Calendar.getInstance();
    calendar.setTimeInMillis(System.currentTimeMillis());
    calendar.set(Calendar.HOUR_OF_DAY, hour);
    calendar.set(Calendar.MINUTE, minute);
    alarmMgr.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), alarmIntent);

在片段中监听AlarmManager，如下所示：

Listens for AlarmManager in Fragment as below:

LocalBroadcastManager.getInstance(getActivity()).registerReceiver(mDashboardUpdateReceiver, new IntentFilter
        (AppConstants.INTENT_ACTION_UPDATE_DASHBOARD));

，如果广播收到，则执行操作：

and performs actions if broadcast receives:

private BroadcastReceiver mDashboardUpdateReceiver = new BroadcastReceiver() {
     @Override
     public void onReceive(Context context, Intent intent) {
         Log.d(TAG, "Dashboard updating...");
         updateCounters();
     }

推荐答案

首先， PendingIntent 不会触发本地广播。您不能在此处使用 LocalBroadcastManager 。

First, a PendingIntent does not trigger a local broadcast. You cannot use LocalBroadcastManager here.

第二，使用 AlarmManager 更新UI很奇怪。如果您的UI存在，则说明您正在运行一个进程，因此可以使用某些进程内的东西（例如 ScheduledExecutorService ），而不用大惊小怪地使用 AlarmManager 。

Second, using AlarmManager to update a UI is rather odd. If your UI exists, you have a process running, so you could use something in-process (e.g., ScheduledExecutorService) rather than fussing with AlarmManager.

第三，您没有考虑设置（Calendar.HOUR_OF_DAY，小时）和 calendar.set（Calendar.MINUTE，分钟）可能会将 Calendar 更改为过去。想象一下，如果您在23:00执行您的第一个代码段，并且 hour 设置为 22 和分钟设置为 0 。您创建的日历对象将用于今天，但今天将用于22:00，这是现在的一个小时（23:00）。您需要检查日历，看看它是否是过去的，如果是，则每天检查 add（）或将其调整为将来的某个时间。

Third, you are not taking into account that set(Calendar.HOUR_OF_DAY, hour) and calendar.set(Calendar.MINUTE, minute) might change the Calendar to be in the past. Imagine if you execute your first code snippet at 23:00, with hour set to be 22 and minute set to be 0. The Calendar object that you create will be for today, but for 22:00 today, which was an hour before now (23:00). You need to check the Calendar, see if it is in the past, and if so, add() a day or otherwise adjust it to some future time.

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