Android告警管理器未在指定时间触发

Question

我正在尝试实现一个通知，让它在未来的某个固定位置触发，但我很难让它正常工作。它会立即触发，而不是在将来的指定时间触发。下面是我的receiver类。我从另一个类调用SetAlarm，并传递一个时间间隔，即alertTime。有什么想法吗？谢谢！

using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Util;

namespace Test_Android
{
[BroadcastReceiver]
class NotificationAlertReceiver : BroadcastReceiver
{

    public NotificationAlertReceiver()
    {

    }

    public override void OnReceive(Context context, Intent intent)
    {
        PowerManager pm = (PowerManager)context.GetSystemService(Context.PowerService);
        PowerManager.WakeLock w1 = pm.NewWakeLock (WakeLockFlags.Partial, "NotificationReceiver");
        w1.Acquire ();
        var nMgr = (NotificationManager)context.GetSystemService (Context.NotificationService);
        var notification = new Notification (Resource.Drawable.loadIcon, "Arrival");
        var pendingIntent = PendingIntent.GetActivity (context, 0, new Intent (context, typeof(MainActivity)), 0);
        notification.SetLatestEventInfo (context, "Arrival", "Arrival", pendingIntent);
        nMgr.Notify (0, notification);
        w1.Release ();
    }

    public void CancelAlarm(Context context){ 
        Intent intent = new Intent(context, this.Class);
        PendingIntent sender = PendingIntent.GetBroadcast (context, 0, intent, 0);
        AlarmManager alarmManager = (AlarmManager) context.GetSystemService (Context.AlarmService);
        alarmManager.Cancel (sender);
    }

    public void SetAlarm(Context context, int alertTime){
        long now = SystemClock.CurrentThreadTimeMillis();
        AlarmManager am = (AlarmManager) context.GetSystemService (Context.AlarmService);
        Intent intent = new Intent(context, this.Class);
        PendingIntent pi = PendingIntent.GetBroadcast (context, 0, intent, 0);
        am.Set (AlarmType.RtcWakeup, now + ((long)(alertTime*10000)), pi);
    }
}
}

Answer 1

你在你的AndroidManifest.xml中注册接收器了吗？

<receiver android:name=".NotificationAlertReceiver "></receiver>

Answer 2

由于您的警报使用的是AlarmType.RtcWakeup，因此您应该使用实时(例如System.currentTimeMillis())而不是线程时间作为"now“变量。

此外，您需要将秒数乘以10,000以得到毫秒数。正确的乘数是1,000。