XXX*_*XXX 435
这是工作代码.它每隔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>
...
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你班上的代码:
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);
}
}
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从服务设置警报:
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;
}
}
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如果要在电话启动时重复设置警报:
向Manifest.xml添加权限和服务:
<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>
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并创建新类:
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);
}
}
}
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And*_*Dev 54
我尝试了XXX的解决方案,虽然它最初工作,但在某些时候它停止工作.该onReceive
从来没有得到再次调用.我花了好几个小时试图找出它可能是什么.我意识到的是,Intent
无论什么神秘的原因不再被召唤.为了解决这个问题,我发现你确实需要在清单中为接收者指定一个动作.例:
<receiver android:name=".Alarm" android:exported="true">
<intent-filter>
<action android:name="mypackage.START_ALARM" >
</action>
</intent-filter>
</receiver>
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请注意,名称".Alarm"
与句点有关.在XXX的setAlarm
方法中,创建Intent
如下:
Intent i = new Intent("mypackage.START_ALARM");
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该START_ALARM
消息可以是你希望它是什么.我只是为了演示目的给了它这个名字.
我没有看到清单中定义的接收器没有指定操作的intent过滤器.按照XXX指定的方式创建它们似乎有点虚伪.通过指定操作名称,Android将被强制创建BroadcastReceiver
使用与操作对应的类的实例.如果您依赖于上下文,请注意Android有几个不同的对象,这些对象都称为上下文,可能不会导致您BroadcastReceiver
创建.强制Android仅使用操作消息创建类的实例远比依赖可能永远不会工作的某些iffy上下文好得多.
amr*_*amr 26
这是一个相当独立的例子.它在5秒后变成红色按钮.
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 );
}
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请记住,即使应用程序未运行,AlarmManager也会触发.如果您调用此功能并点击主页按钮,等待5秒钟,然后返回到您的应用程序,该按钮将变为红色.
如果您的应用程序根本不在内存中,我不知道您将获得什么样的行为,因此请注意您尝试保留的状态.
M.U*_*man 14
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();
}
}
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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();
}
}
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AndroidManifest.xml中
<?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>
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AlarmManager
结合IntentService
我认为最好的使用模式AlarmManager
是它与IntentService
. 由IntentService
触发AlarmManager
,它通过接收意图处理所需的操作。这种结构没有像使用BroadcastReceiver
. 我在kotlin 中为这个想法开发了一个示例代码,可在此处获得:
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)
}
}
}
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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"
}
}
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清单文件
<?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>
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用法:
val calendar = Calendar.getInstance()
calendar.add(Calendar.SECOND, 10)
MyAlarmManager.setAlarm(applicationContext, calendar.timeInMillis, "Test Message!")
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如果你想取消预定的闹钟,试试这个:
MyAlarmManager.cancelAlarm(applicationContext)
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