为什么我在使用setExact时指定的时间没有触发警报？

Question

我正在尝试设置提醒功能。用户将输入时间，点击按钮，此时将发送通知。但是，尽管我已经开启了我的代码，但我还是无法在确切的时间触发通知。以下是我的服务，接收器，活动和清单的代码。我甚至尝试过.setWindow（），但无论我尝试什么，我通常会在5-10分钟内得到通知....如果有延迟，如果可能的话，它不会超过一分钟。任何帮助将不胜感激。

清单

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ocv.pushbeta">

<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACTION_VIEW" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- App receives GCM messages. -->
<permission
    android:name="com.ocv.pushbeta.permission.C2D_MESSAGE"
    android:protectionLevel="signature" />

<uses-permission android:name="com.ocv.pushbeta.permission.C2D_MESSAGE" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name=".permission.C2D_MESSAGE" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.CAMERA" />



<application
    android:allowBackup="true"
    android:icon="@drawable/blankappmainicon"
    android:label="Push Beta">

    <receiver
        android:name="com.google.android.gcm.GCMBroadcastReceiver"
        android:permission="com.google.android.c2dm.permission.SEND" >
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <action android:name="com.google.android.c2dm.intent.REGISTRATION" />

            <category android:name="com.ocv.pushbeta" />
        </intent-filter>
    </receiver>
    <receiver android:name=".AlarmReceiver" />
    <service android:name=".GCMIntentService" />
    <service android:name=".AlarmService"
             android:enabled="true" />



    <activity
        android:name=".MenuActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity android:name=".APITest"
        android:theme="@style/Theme.AppCompat.Light"/>

    <activity
        android:name=".SettingsActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.NoActionBar" />

    <activity android:name=".ReadTextFileActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.NoActionBar"/>

    <activity android:name=".PushActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.NoActionBar"/>
    <activity android:name=".AlarmActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.NoActionBar"/>

</application>

活动

package com.ocv.pushbeta;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.ToggleButton;

import java.util.Calendar;

public class AlarmActivity extends Activity {

    AlarmManager alarmManager;
    private PendingIntent pendingIntent;
    private TimePicker alarmTimePicker;
    private static AlarmActivity inst;
    private TextView alarmTextView;

    public static AlarmActivity instance() {
        return inst;
    }

    @Override
    public void onStart() {
        super.onStart();
        inst = this;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        alarmTimePicker = (TimePicker) findViewById(R.id.alarmTimePicker);
        alarmTextView = (TextView) findViewById(R.id.alarmText);
        ToggleButton alarmToggle = (ToggleButton) findViewById(R.id.alarmToggle);
        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
    }

    public void onToggleClicked(View view) {
        if (((ToggleButton) view).isChecked()) {
            Log.d("MyActivity", "Alarm On");
            Calendar calendar = Calendar.getInstance();
            calendar.set(Calendar.HOUR_OF_DAY, alarmTimePicker.getCurrentHour());
            calendar.set(Calendar.MINUTE, alarmTimePicker.getCurrentMinute());
            calendar.set(Calendar.SECOND, 0);
            calendar.set(Calendar.MILLISECOND, 0);
            Intent myIntent = new Intent(AlarmActivity.this, AlarmReceiver.class);

            pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, MenuActivity.GenID(), myIntent, 0);

            if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT){
                Log.d("MyActivity", "SDK Higher than 19...setting exact");
                //alarmManager.setExact(AlarmManager.RTC, calendar.getTimeInMillis(), pendingIntent);
                alarmManager.setExact(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
            }else{
            Log.d("MyActivity", "SDK lower than 19...Alarm will be off");
            alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
            }

        } else {
            alarmManager.cancel(pendingIntent);
            setAlarmText("");
            Log.d("MyActivity", "Alarm Off");
        }
    }

    public void setAlarmText(String alarmText) {
        alarmTextView.setText(alarmText);
    }
}

服务

package com.ocv.pushbeta;

import android.app.IntentService;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

import java.util.Calendar;
import java.util.Date;

public class AlarmService extends IntentService {
    private NotificationManager alarmNotificationManager;

    public AlarmService() {
        super("AlarmService");
    }

    @Override
    public void onHandleIntent(Intent intent) {
        sendNotification("Wake Up! Wake Up!");
    }

    private void sendNotification(String msg) {
        Log.d("AlarmService", "Preparing to send notification...: " + msg);
        alarmNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);

        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, MenuActivity.class), 0);

        NotificationCompat.Builder alamNotificationBuilder = new NotificationCompat.Builder(
                this).setContentTitle("Alarm").setSmallIcon(R.drawable.ic_lock_black_24dp)
                .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
                .setContentText(msg);




        alamNotificationBuilder.setContentIntent(contentIntent);
        alarmNotificationManager.notify(MenuActivity.GenID(), alamNotificationBuilder.build());
        Log.d("AlarmService", "Notification sent.");
    }
}

接收机

package com.ocv.pushbeta;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.media.Ringtone;
import android.media.RingtoneManager;
import android.net.Uri;
import android.support.v4.content.WakefulBroadcastReceiver;

public class AlarmReceiver extends WakefulBroadcastReceiver {

    @Override
    public void onReceive(final Context context, Intent intent) {
        //this will update the UI with message
//        MenuActivity inst = MenuActivity.instance();
//        inst.setAlarmText("Alarm! Wake up! Wake up!");

        //this will sound the alarm tone
        //this will sound the alarm once, if you wish to
        //raise alarm in loop continuously then use MediaPlayer and setLooping(true)
//        Uri alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_ALARM);
//        if (alarmUri == null) {
//            alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
//        }
//        Ringtone ringtone = RingtoneManager.getRingtone(context, alarmUri);
//        ringtone.play();

        //this will send a notification message
        ComponentName comp = new ComponentName(context.getPackageName(),
                AlarmService.class.getName());
        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
    }
}

编辑 - 请尽量避免链接到其他问题。我已经谷歌搜索了这个主题，然后直到我得到答案，我将继续谷歌，所以我至少可以看到每个Stack Overflow上的主题。