MainActivity.java

package com.example.alarmexample;  

import android.app.Activity;  
import android.app.AlarmManager;  
import android.app.PendingIntent;  
import android.content.Intent;  
import android.os.Bundle;  
import android.view.View;  
import android.view.View.OnClickListener;  
import android.widget.Button;  
import android.widget.EditText;  
import android.widget.Toast;  

public class MainActivity extends Activity {  
Button b1;  

    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main); 

        startAlert();  

}   public void startAlert() { 
        int timeInSec = 2;

        Intent intent = new Intent(this, MyBroadcastReceiver.class);  
        PendingIntent pendingIntent = PendingIntent.getBroadcast(  
                                      this.getApplicationContext(), 234, intent, 0);  
        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);  
        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (timeInSec * 1000), pendingIntent);  
        Toast.makeText(this, "Alarm set to after " + i + " seconds",Toast.LENGTH_LONG).show();  
    }  

}

MyBroadcastReceiver.java

package com.example.alarmexample;  

import android.content.BroadcastReceiver;  
import android.content.Context;  
import android.content.Intent;  
import android.media.MediaPlayer;  
import android.widget.Toast;  

public class MyBroadcastReceiver extends BroadcastReceiver {  
    MediaPlayer mp;  
    @Override  
    public void onReceive(Context context, Intent intent) {  
        mp=MediaPlayer.create(context, R.raw.alarm);  
        mp.start();  
        Toast.makeText(context, "Alarm", Toast.LENGTH_LONG).show();  
    }  
}  

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>  
<manifest xmlns:android="http://schemas.android.com/apk/res/android"  
    package="com.example.alarmexample" >  

    <uses-permission android:name="android.permission.VIBRATE" />  


    <application  
        android:allowBackup="true"  
        android:icon="@drawable/ic_launcher"  
        android:label="@string/app_name"  
        android:theme="@style/AppTheme" >  

        <activity  
            android:name="com.example.alarmexample.MainActivity"  
            android:label="@string/app_name" >  
            <intent-filter>  
                <action android:name="android.intent.action.MAIN" />  

                <category android:name="android.intent.category.LAUNCHER" />  
            </intent-filter>  
        </activity>  

        <receiver android:name="MyBroadcastReceiver" >  
        </receiver>  
    </application>  

</manifest>  

这是工作代码。它每10分钟唤醒一次CPU，直到手机关机。

添加到Manifest.xml:

...
<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission>
...
<receiver android:process=":remote" android:name=".Alarm"></receiver>
...

类中的代码:

package yourPackage;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.PowerManager;
import android.widget.Toast;

public class Alarm extends BroadcastReceiver 
{    
    @Override
    public void onReceive(Context context, Intent intent) 
    {   
        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "");
        wl.acquire();

        // Put here YOUR code.
        Toast.makeText(context, "Alarm !!!!!!!!!!", Toast.LENGTH_LONG).show(); // For example

        wl.release();
    }

    public void setAlarm(Context context)
    {
        AlarmManager am =( AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
        Intent i = new Intent(context, Alarm.class);
        PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
        am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 1000 * 60 * 10, pi); // Millisec * Second * Minute
    }

    public void cancelAlarm(Context context)
    {
        Intent intent = new Intent(context, Alarm.class);
        PendingIntent sender = PendingIntent.getBroadcast(context, 0, intent, 0);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        alarmManager.cancel(sender);
    }
}

设置来自服务的告警:

package yourPackage;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;

public class YourService extends Service
{
    Alarm alarm = new Alarm();
    public void onCreate()
    {
        super.onCreate();       
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) 
    {
        alarm.setAlarm(this);
        return START_STICKY;
    }

   @Override        
   public void onStart(Intent intent, int startId)
    {
        alarm.setAlarm(this);
    }

    @Override
    public IBinder onBind(Intent intent) 
    {
        return null;
    }
}

如果您想设置开机时重复闹铃:

将权限和服务添加到Manifest.xml:

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"></uses-permission>
...
<receiver android:name=".AutoStart">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
    </intent-filter>
</receiver>
...
<service
        android:name=".YourService"
        android:enabled="true"
        android:process=":your_service" >
</service>

并创建一个新类:

package yourPackage;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class AutoStart extends BroadcastReceiver
{   
    Alarm alarm = new Alarm();
    @Override
    public void onReceive(Context context, Intent intent)
    {   
        if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED))
        {
            alarm.setAlarm(context);
        }
    }
}

报警经理:

添加到XML布局(*初始化这些视图在创建在主活动)

  <TimePicker
    android:id="@+id/timepicker"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="2"></TimePicker>

  <Button
    android:id="@+id/btn_start"
    android:text="start Alarm"
    android:onClick="start_alarm_event"
    android:layout_width="match_parent"
    android:layout_height="52dp" />

添加到清单(内部应用程序标签&&外部活动)

 <receiver android:name=".AlarmBroadcastManager"
        android:enabled="true"
        android:exported="true"/>

创建AlarmBroadcastManager类(从BroadcastReceiver继承)

 public class AlarmBroadcastManager extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
      MediaPlayer mediaPlayer=MediaPlayer.create(context,Settings.System.DEFAULT_RINGTONE_URI);
      mediaPlayer.start();
    }
 }

在Main Activity中(添加这些功能):

 @RequiresApi(api = Build.VERSION_CODES.M)
 public  void start_alarm_event(View view){
    Calendar calendar=Calendar.getInstance();
    calendar.set(
    calendar.get(Calendar.YEAR),
    calendar.get(Calendar.MONTH),
    calendar.get(Calendar.DAY_OF_MONTH),
    timePicker.getHour(),
    timePicker.getMinute(),
    0
    );
    setAlarm(calendar.getTimeInMillis());
 }

 public void setAlarm(long timeInMillis){
    AlarmManager alarmManager=(AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent=new Intent(this,AlarmBroadcastManager.class);
    PendingIntent pendingIntent=PendingIntent.getBroadcast(this,0,intent,0);
     alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,timeInMillis,AlarmManager.INTERVAL_DAY,pendingIntent);
    Toast.makeText(getApplicationContext(),"Alarm is Set",Toast.LENGTH_SHORT).show();


 }

这里有一个相当独立的例子。5秒后按钮变为红色。

    public void SetAlarm()
    {
        final Button button = buttons[2]; // replace with a button from your own UI
        BroadcastReceiver receiver = new BroadcastReceiver() {
            @Override public void onReceive( Context context, Intent _ )
            {
                button.setBackgroundColor( Color.RED );
                context.unregisterReceiver( this ); // this == BroadcastReceiver, not Activity
            }
        };

        this.registerReceiver( receiver, new IntentFilter("com.blah.blah.somemessage") );

        PendingIntent pintent = PendingIntent.getBroadcast( this, 0, new Intent("com.blah.blah.somemessage"), 0 );
        AlarmManager manager = (AlarmManager)(this.getSystemService( Context.ALARM_SERVICE ));

        // set alarm to fire 5 sec (1000*5) from now (SystemClock.elapsedRealtime())
        manager.set( AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 1000*5, pintent );
    }

请记住，即使在应用程序未运行时，AlarmManager也会触发。如果你调用这个函数并点击Home键，等待5秒，然后回到你的应用程序，按钮将变成红色。

我不知道如果你的应用程序根本不在内存中，你会得到什么样的行为，所以要小心你试图保存什么样的状态。

我在Android上也遇到了警报问题。问题是关于打盹模式(https://developer.android.com/training/monitoring-device-state/doze-standby)。例如，当我把闹钟调到一个小时后，它就正常了，但如果我把它调到凌晨4点，它就不工作了。我刚刚发现这是非常简单的，我只是应该使用AlarmManager.setAlarmClock()而不是AlarmManager.set()。

所以我决定在github上创建一个示例应用程序。 https://github.com/carlosabreu/androidalarm

•AlarmManager与IntentService结合使用

我认为使用AlarmManager的最佳模式是它与IntentService的协作。IntentService由AlarmManager触发，它通过接收意图处理所需的操作。这种结构不像使用BroadcastReceiver那样对性能有影响。我在kotlin中为这个想法开发了一个示例代码，可以在这里获得:

MyAlarmManager.kt

import android.app.AlarmManager
import android.app.PendingIntent
import android.content.Context
import android.content.Intent

object MyAlarmManager {

    private var pendingIntent: PendingIntent? = null

    fun setAlarm(context: Context, alarmTime: Long, message: String) {
        val alarmManager: AlarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager

        val intent = Intent(context, MyIntentService::class.java)
        intent.action = MyIntentService.ACTION_SEND_TEST_MESSAGE
        intent.putExtra(MyIntentService.EXTRA_MESSAGE, message)

        pendingIntent = PendingIntent.getService(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT)
        alarmManager.set(AlarmManager.RTC_WAKEUP, alarmTime, pendingIntent)
    }

    fun cancelAlarm(context: Context) {
        pendingIntent?.let {
            val alarmManager: AlarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
            alarmManager.cancel(it)
        }
    }

}

MyIntentService.kt

import android.app.IntentService
import android.content.Intent

class MyIntentService : IntentService("MyIntentService") {

    override fun onHandleIntent(intent: Intent?) {
        intent?.apply {
            when (intent.action) {
                ACTION_SEND_TEST_MESSAGE -> {
                    val message = getStringExtra(EXTRA_MESSAGE)
                    println(message)
                }
            }
        }
    }

    companion object {
        const val ACTION_SEND_TEST_MESSAGE = "ACTION_SEND_TEST_MESSAGE"
        const val EXTRA_MESSAGE = "EXTRA_MESSAGE"
    }

}

manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.aminography.alarm">

    <application
        ... >

    <service
        android:name="path.to.MyIntentService"
        android:enabled="true"
        android:stopWithTask="false" />

    </application>

</manifest>

用法:

val calendar = Calendar.getInstance()
calendar.add(Calendar.SECOND, 10)
MyAlarmManager.setAlarm(applicationContext, calendar.timeInMillis, "Test Message!")

如果你想取消预定的闹钟，试试这个:

MyAlarmManager.cancelAlarm(applicationContext)