•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)

这段代码将帮助您制作重复警报。重复时间可由您设置。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
     <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical" 
     android:background="#000000"
     android:paddingTop="100dp">

    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center" >

    <EditText
        android:id="@+id/ethr"
    android:layout_width="50dp"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="Hr"
    android:singleLine="true" >


        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/etmin"
    android:layout_width="55dp"
    android:layout_height="wrap_content"

    android:ems="10"
    android:hint="Min"
    android:singleLine="true" />

    <EditText
        android:id="@+id/etsec"
    android:layout_width="50dp"
    android:layout_height="wrap_content"

    android:ems="10"
    android:hint="Sec"
    android:singleLine="true" />

    </LinearLayout>

   <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content" 
    android:gravity="center"
    android:paddingTop="10dp">


    <Button
        android:id="@+id/setAlarm"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClickSetAlarm"
        android:text="Set Alarm" />

</LinearLayout>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity {
    int hr = 0;
    int min = 0;
    int sec = 0;
    int result = 1;

    AlarmManager alarmManager;
    PendingIntent pendingIntent;
    BroadcastReceiver mReceiver;

    EditText ethr;
    EditText etmin;
    EditText etsec;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ethr = (EditText) findViewById(R.id.ethr);
        etmin = (EditText) findViewById(R.id.etmin);
        etsec = (EditText) findViewById(R.id.etsec);
        RegisterAlarmBroadcast();
    } 

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    protected void onDestroy() {
        unregisterReceiver(mReceiver);
        super.onDestroy();
    }

    public void onClickSetAlarm(View v) {
        String shr = ethr.getText().toString();
        String smin = etmin.getText().toString();
        String ssec = etsec.getText().toString();

        if(shr.equals("")) 
            hr = 0;
        else {
            hr = Integer.parseInt(ethr.getText().toString());
            hr=hr*60*60*1000;
        }

        if(smin.equals(""))
            min = 0;
        else {
            min = Integer.parseInt(etmin.getText().toString());
            min = min*60*1000;
        }

        if(ssec.equals(""))
            sec = 0;
        else {
             sec = Integer.parseInt(etsec.getText().toString());
             sec = sec * 1000;
        }
        result = hr+min+sec;
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), result , pendingIntent); 
    }

    private void RegisterAlarmBroadcast() {
        mReceiver = new BroadcastReceiver() {
            // private static final String TAG = "Alarm Example Receiver";
            @Override
            public void onReceive(Context context, Intent intent) {
                Toast.makeText(context, "Alarm time has been reached", Toast.LENGTH_LONG).show();
            }
        };

        registerReceiver(mReceiver, new IntentFilter("sample"));
        pendingIntent = PendingIntent.getBroadcast(this, 0, new Intent("sample"), 0);
        alarmManager = (AlarmManager)(this.getSystemService(Context.ALARM_SERVICE));
    }

    private void UnregisterAlarmBroadcast() {
        alarmManager.cancel(pendingIntent); 
        getBaseContext().unregisterReceiver(mReceiver);
    }
}

如果你只需要报警一次，那么更换

alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), result , pendingIntent);

with

 alarmManager.set( AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + result , pendingIntent );

我尝试了XXX的解决方案，虽然它最初确实有效，但在某种程度上它停止了工作。onReceive再也没有被调用。我花了好几个小时想知道那是什么。我开始意识到，出于某种神秘的原因，意图不再被召唤。为了解决这个问题，我发现确实需要在清单中为接收者指定一个操作。例子:

<receiver android:name=".Alarm" android:exported="true">
    <intent-filter>
        <action android:name="mypackage.START_ALARM" >
        </action>
    </intent-filter>
</receiver> 

请注意，名称是“。“Alarm”和周期。在XXX的setAlarm方法中，创建Intent，如下所示:

Intent i = new Intent("mypackage.START_ALARM");

START_ALARM消息可以是您想要的任何消息。我这样命名只是为了演示。

I have not seen receivers defined in the manifest without an intent filter that specifies the action. Creating them the way XXX has specified it seems kind of bogus. By specifying the action name, Android will be forced to create an instance of the BroadcastReceiver using the class that corresponds to the action. If you rely upon context, be aware that Android has several different objects that are ALL called context and may not result in getting your BroadcastReceiver created. Forcing Android to create an instance of your class using only the action message is far better than relying upon some iffy context that may never work.

我已经用最简单的方式实现了这一点。

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

import junit.framework.Assert;

/**
 * Created by Daniel on 28/08/2016.
 */
public abstract class AbstractSystemServiceTask {

    private final Context context;
    private final AlarmManager alarmManager;
    private final BroadcastReceiver broadcastReceiver;
    private final PendingIntent pendingIntent;

    public AbstractSystemServiceTask(final Context context, final String id, final long time, final AlarmType alarmType, final BackgroundTaskListener backgroundTaskListener) {

        Assert.assertNotNull("ApplicationContext can't be null", context);
        Assert.assertNotNull("ID can't be null", id);

        this.context = context;

        this.alarmManager = (AlarmManager) this.context.getSystemService(Context.ALARM_SERVICE);

        this.context.registerReceiver(
                this.broadcastReceiver = this.getBroadcastReceiver(backgroundTaskListener),
                new IntentFilter(id));

        this.configAlarmManager(
                this.pendingIntent = PendingIntent.getBroadcast(this.context, 0, new Intent(id), 0),
                time,
                alarmType);
    }

    public void stop() {

        this.alarmManager.cancel(this.pendingIntent);
        this.context.unregisterReceiver(this.broadcastReceiver);
    }

    private BroadcastReceiver getBroadcastReceiver(final BackgroundTaskListener backgroundTaskListener) {

        Assert.assertNotNull("BackgroundTaskListener can't be null.", backgroundTaskListener);

        return new BroadcastReceiver() {

            @Override
            public void onReceive(Context context, Intent intent) {

                backgroundTaskListener.perform(context, intent);
            }
        };
    }

    private void configAlarmManager(final PendingIntent pendingIntent, final long time, final AlarmType alarmType) {

        long ensurePositiveTime = Math.max(time, 0L);

        switch (alarmType) {
            case REPEAT:
                this.alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), ensurePositiveTime, pendingIntent);
                break;
            case ONE_TIME:
            default:
                this.alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + ensurePositiveTime, pendingIntent);
        }
    }

    public interface BackgroundTaskListener {

        void perform(Context context, Intent intent);

    }

    public enum AlarmType {

        REPEAT, ONE_TIME;

    }

}

唯一的下一步就是执行它。

import android.content.Context;
import android.content.Intent;
import android.util.Log;

import ...AbstractSystemServiceTask;

import java.util.concurrent.TimeUnit;

/**
 * Created by Daniel on 28/08/2016.
 */
public class UpdateInfoSystemServiceTask extends AbstractSystemServiceTask {

    private final static String ID = "UPDATE_INFO_SYSTEM_SERVICE";
    private final static long REPEAT_TIME = TimeUnit.SECONDS.toMillis(10);
    private final static AlarmType ALARM_TYPE = AlarmType.REPEAT;

    public UpdateInfoSystemServiceTask(Context context) {

        super(context, ID, REPEAT_TIME, ALARM_TYPE, new BackgroundTaskListener() {

            @Override
            public void perform(Context context, Intent intent) {

                Log.i("MyAppLog", "-----> UpdateInfoSystemServiceTask");

                //DO HERE WHATEVER YOU WANT...
            }
        });

        Log.i("MyAppLog", "UpdateInfoSystemServiceTask started.");
    }

}

我喜欢使用这个实现，但另一种可能的好方法是，不要使AbstractSystemServiceTask类抽象，而是通过Builder来构建它。

我希望它能帮助你。

更新 改进了允许同一个BroadCastReceiver上有多个BackgroundTaskListener。

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

import junit.framework.Assert;

import java.util.HashSet;
import java.util.Set;

/**
 * Created by Daniel on 28/08/2016.
 */
public abstract class AbstractSystemServiceTask {

    private final Context context;
    private final AlarmManager alarmManager;
    private final BroadcastReceiver broadcastReceiver;
    private final PendingIntent pendingIntent;

    private final Set<BackgroundTaskListener> backgroundTaskListenerSet;

    public AbstractSystemServiceTask(final Context context, final String id, final long time, final AlarmType alarmType) {

        Assert.assertNotNull("ApplicationContext can't be null", context);
        Assert.assertNotNull("ID can't be null", id);

        this.backgroundTaskListenerSet = new HashSet<>();

        this.context = context;

        this.alarmManager = (AlarmManager) this.context.getSystemService(Context.ALARM_SERVICE);

        this.context.registerReceiver(
                this.broadcastReceiver = this.getBroadcastReceiver(),
                new IntentFilter(id));

        this.configAlarmManager(
                this.pendingIntent = PendingIntent.getBroadcast(this.context, 0, new Intent(id), 0),
                time,
                alarmType);
    }

    public synchronized void registerTask(final BackgroundTaskListener backgroundTaskListener) {

        Assert.assertNotNull("BackgroundTaskListener can't be null", backgroundTaskListener);

        this.backgroundTaskListenerSet.add(backgroundTaskListener);
    }

    public synchronized void removeTask(final BackgroundTaskListener backgroundTaskListener) {

        Assert.assertNotNull("BackgroundTaskListener can't be null", backgroundTaskListener);

        this.backgroundTaskListenerSet.remove(backgroundTaskListener);
    }

    public void stop() {

        this.backgroundTaskListenerSet.clear();

        this.alarmManager.cancel(this.pendingIntent);
        this.context.unregisterReceiver(this.broadcastReceiver);
    }

    private BroadcastReceiver getBroadcastReceiver() {

        return new BroadcastReceiver() {

            @Override
            public void onReceive(final Context context, final Intent intent) {

                for (BackgroundTaskListener backgroundTaskListener : AbstractSystemServiceTask.this.backgroundTaskListenerSet) {

                    backgroundTaskListener.perform(context, intent);
                }
            }
        };
    }

    private void configAlarmManager(final PendingIntent pendingIntent, final long time, final AlarmType alarmType) {

        long ensurePositiveTime = Math.max(time, 0L);

        switch (alarmType) {
            case REPEAT:
                this.alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), ensurePositiveTime, pendingIntent);
                break;
            case ONE_TIME:
            default:
                this.alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + ensurePositiveTime, pendingIntent);
        }
    }

    public interface BackgroundTaskListener {

        void perform(Context context, Intent intent);

    }

    public enum AlarmType {

        REPEAT, ONE_TIME;

    }

}

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

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。