Question

我有这段代码：

namespace TestB
{
    [Activity(Label = "TestB", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity
    {
        Java.Util.Calendar calendar;
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            SetContentView(Resource.Layout.Main);
            Button button = FindViewById<Button>(Resource.Id.MyButton);

            try
            {
                calendar = Java.Util.Calendar.Instance;
                calendar.TimeInMillis = Java.Lang.JavaSystem.CurrentTimeMillis();
            }
            catch (Exception ex)
            {
                Toast.MakeText(this, ex.Message.ToString(), ToastLength.Short).Show();
            }
        }
        protected override void OnDestroy()
        {
            base.OnDestroy();
            if (calendar.Get(Java.Util.CalendarField.HourOfDay) == 13 && calendar.Get(Java.Util.CalendarField.Minute) == 33)
                Toast.MakeText(this, calendar.Get(Java.Util.CalendarField.HourOfDay).ToString() + " " + calendar.Get(Java.Util.CalendarField.Minute).ToString(), ToastLength.Short).Show();
        }
        protected override void OnPause()
        {
            base.OnPause();
            if (calendar.Get(Java.Util.CalendarField.HourOfDay) == 13 && calendar.Get(Java.Util.CalendarField.Minute) == 33)
                Toast.MakeText(this, calendar.Get(Java.Util.CalendarField.HourOfDay).ToString() + " " + calendar.Get(Java.Util.CalendarField.Minute).ToString(), ToastLength.Short).Show();
        }

当时间到达13和33分钟时，将不会发出消息。我想以这种方式调用alarmManager。我希望calendar.Set(Java.Util.CalendarField.HourOfDay, 13)和calendar.Set(Java.Util.CalendarField.Minute, 33)并以这种方式致电alarmManager。

编辑1：

我编辑了这段代码：

System.Timers.Timer t;
                if (t == null)
                {
                    t = new System.Timers.Timer();
                    //t.Elapsed += new System.Timers.ElapsedEventHandler(t_Elapsed);
                    //t.Elapsed += (sender, args) => FireTheMissiles();
                    t.Elapsed += new System.Timers.ElapsedEventHandler(OnTimeEvent);
                    t.Interval = 1000;
                    t.Enabled = true;
                }
                t.Start();
        protected override void OnStop()
        {
            base.OnStop();
            flag = 3;
        }
        private void OnTimeEvent(object source, ElapsedEventArgs e)
        {
            h = DateTime.Now.Hour;
            m = DateTime.Now.Minute;

            RunOnUiThread(delegate
            {
                if (flag == 3)
                {
                    if (calendar.Get(Java.Util.CalendarField.HourOfDay) == h && calendar.Get(Java.Util.CalendarField.Minute) == m)
                        Toast.MakeText(this, "3 " + calendar.Get(Java.Util.CalendarField.HourOfDay).ToString() + " " + calendar.Get(Java.Util.CalendarField.Minute).ToString(), ToastLength.Short).Show();
                }
            });
        }

我让我的朋友在另一个应用程序上实现这个项目，看看如果应用程序24小时没有打开就会出现一条消息，但是不会出现任何消息。

编辑2：

我用了你的代码我也用过计时器我将安装的时间和日期等信息保存在数据库中我希望闹钟按时间和日期显示但经过多次尝试，我没有收到任何警告信息。

private void OnTimeEvent(object source, ElapsedEventArgs e)
{
    RunOnUiThread(delegate
    {
        if (flag == 1)
        {
        }
        int h = DateTime.Now.Hour;
        int m = DateTime.Now.Minute;
        DateTime today = DateTime.Today;
        dc = today.AddDays(1).Day;
        mc = today.AddDays(1).Month;
        yc = today.AddDays(1).Year;
        var data = mydb.Table<DatB>();
        var data1 = data.Where(x => x.DWSeen == dc).Where(x => x.MWSeen == mc).FirstOrDefault();
        if (flag == 3 && data1 != null && data1.RFSeen == 0)
        {
            startAlertAtParticularTime(data1.HourSeen, data1.MinuteSeen, "-1");
            if (calendar.Get(Java.Util.CalendarField.HourOfDay) == h && calendar.Get(Java.Util.CalendarField.Minute) == m && calendar.Get(Java.Util.CalendarField.DayOfMonth) == dc && calendar.Get(Java.Util.CalendarField.Month) == mc && calendar.Get(Java.Util.CalendarField.Year) == yc && data1.RFSeen == 0)
            {
                startAlertAtParticularTime(data1.HourSeen, data1.MinuteSeen, data1.RFSeen.ToString());
            }
        }
    });
}

＆＃34; -1＆＃34;表示警报不会出现＆＃34; 0＆＃34;表示将出现警报

namespace TestB
{
    [BroadcastReceiver(Enabled = true)]
    public class MyBR: BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent intent)
        {
            string dataSeenResult = intent.GetStringExtra("dataSeen");
            if ((MyApp.isActivityVisible() == "Stopped" || MyApp.isActivityVisible() == "Destroyed") && dataSeenResult == "0")
            {
                Toast.MakeText(context, MyApp.isActivityVisible().ToString(), ToastLength.Short).Show();
            }
        }
    }
}

Answer 1

是的我希望应用程序在关闭时的特定时间发出警报

首先，您需要创建一个BroadcastReceiver来处理来自系统的警报通知。然后，您可以使用AlarmManager在OnPause或OnDestroy中设置闹钟：

Intent myintent = new Intent(this, typeof(AlarmReceiver));
var pendingintent = PendingIntent.GetBroadcast(this, 0, myintent, PendingIntentFlags.UpdateCurrent);

Java.Util.Date date = new Java.Util.Date();
Java.Util.Calendar cal = Java.Util.Calendar.Instance;
calendar.TimeInMillis = Java.Lang.JavaSystem.CurrentTimeMillis();
cal.Set(Java.Util.CalendarField.HourOfDay, 13);
cal.Set(Java.Util.CalendarField.Minute, 33);
cal.Set(Java.Util.CalendarField.Second, 0);
AlarmManager alarmManager = this.GetSystemService(AlarmService) as AlarmManager;
alarmManager.Set(AlarmType.RtcWakeup, cal.TimeInMillis, pendingintent);

对于BroadcastReceiver部分，在这种情况下，您可以参考Cheesebaron的答案：Xamarin AlarmManager Android。

从OnDestroy或OnPause中的日历获取数据

1 个答案: