MainActivity.java // 它包含在一个文本视图上 tvTime
public class MainActivity extends Activity {
private SampleAlarmReceiver alarm;
private ListView listView;
private ArrayList<String> times;
private ArrayAdapter mAdapter;
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
displayTime();
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView);
alarm = new SampleAlarmReceiver();
alarm.setAlarm(this);
times = new ArrayList<>();
Calendar c = Calendar.getInstance();
String time = c.get(Calendar.HOUR) + ":" + c.get(Calendar.MINUTE) + ":" + c.get(Calendar.SECOND);
times.add(time);
mAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, times);
listView.setAdapter(mAdapter);
}
@Override
protected void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("display_time"));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// When the user clicks START ALARM, set the alarm.
case R.id.start_action:
alarm.setAlarm(this);
return true;
// When the user clicks CANCEL ALARM, cancel the alarm.
case R.id.cancel_action:
alarm.cancelAlarm(this);
return true;
}
return false;
}
@Override
protected void onDestroy() {
super.onDestroy();
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
}
@SuppressLint("SetTextI18n")
public void displayTime() {
Calendar c = Calendar.getInstance();
String time = c.get(Calendar.HOUR) + ":" + c.get(Calendar.MINUTE) + ":" + c.get(Calendar.SECOND);
times.add(time);
mAdapter.notifyDataSetChanged();
}
}
SampleAlarmReceiver.java
public class SampleAlarmReceiver extends WakefulBroadcastReceiver {
// The app's AlarmManager, which provides access to the system alarm services.
private AlarmManager alarmMgr;
// The pending intent that is triggered when the alarm fires.
private PendingIntent alarmIntent;
@Override
public void onReceive(Context context, Intent intent) {
Intent intent1 = new Intent("display_time");
// You can also include some extra data.
LocalBroadcastManager.getInstance(context).sendBroadcast(intent1);
}
// BEGIN_INCLUDE(set_alarm)
/**
* Sets a repeating alarm that runs once a day at approximately 8:30 a.m. When the
* alarm fires, the app broadcasts an Intent to this WakefulBroadcastReceiver.
*
* @param context given context
*/
public void setAlarm(Context context) {
alarmMgr = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, SampleAlarmReceiver.class);
alarmIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
alarmMgr.setInexactRepeating(AlarmManager.RTC_WAKEUP,
5 * 60 * 1000, // After five minute
5 * 60 * 1000, // Every five minute
alarmIntent);
// Enable {@code SampleBootReceiver} to automatically restart the alarm when the
// device is rebooted.
ComponentName receiver = new ComponentName(context, SampleBootReceiver.class);
PackageManager pm = context.getPackageManager();
pm.setComponentEnabledSetting(receiver,
PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
PackageManager.DONT_KILL_APP);
}
/**
* Cancels the alarm.
*
* @param context given context
*/
public void cancelAlarm(Context context) {
// If the alarm has been set, cancel it.
if (alarmMgr != null) {
alarmMgr.cancel(alarmIntent);
}
// Disable {@code SampleBootReceiver} so that it doesn't automatically restart the
// alarm when the device is rebooted.
ComponentName receiver = new ComponentName(context, SampleBootReceiver.class);
PackageManager pm = context.getPackageManager();
pm.setComponentEnabledSetting(receiver,
PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
PackageManager.DONT_KILL_APP);
}
}
SampleBootReceiver.java
public class SampleBootReceiver extends BroadcastReceiver {
SampleAlarmReceiver alarm;
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED"))
{
alarm = new SampleAlarmReceiver();
alarm.setAlarm(context);
}
}
}
main.xml // 它是 MainActivity 中使用的菜单
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/start_action"
android:title="Start Alarm"
app:showAsAction="ifRoom|withText" />
<item
android:id="@+id/cancel_action"
android:title="Stop Alarm"
app:showAsAction="ifRoom|withText" />
</menu>
manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.alarmmanager">
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name=".SampleAlarmReceiver" />
<receiver
android:name=".SampleBootReceiver"
android:enabled="false">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
</application>
</manifest>