Braodcast Receiver顾名思义就是广播接收器，它和时间处理机制类似，但是事件处理机制是程序组件级别的（比如：按钮的单击事件），而广播事件处理机制是系统级别的。我们可以用Intent来启动一个组件，也可以用sendBroadcast()方法发起一个系统级别的事件广播来传递消息。我们同样可以在自己的应用程序中实现Broadcast Receiver来监听和响应广播的Intent。

事件的广播通过创建Intent对象并调用sendBroadcast()方法将广播发出。事件的接受是通过定义一个继承BroadcastReceiver的类来实现的，继承该类后覆盖其onReceive()方法，在该方法中响应时间。

下面是android系统中定义了很多标准的Broadcast Action来响应系统的广播事件。

①ACTION_TIME_CHANGED（时间改变时触发）

②ACTION_BOOT_COMPLETED(系统启动完成后触发)--比如有些程序开机后启动就是用这种方式来实现的

③ACTION_PACKAGE_ADDED（添加包时触发）

④ACTION_BATTERY_CHANGED（电量低时触发）

详细：标准广播ACTION常量

常量名称

常量值

意义

ACTION_BOOT_COMPLETED

android.intent.action.BOOT_COMPLETED

系统启动完成

ACTION_TIME_CHANGED

android.intent.action.ACTION_TIME_CHANGED

时间改变

ACITON_DATE_CHANGED

android.intent.action.ACTION_DATE_CHANGED

日期改变

ACTION_TIMEZONE_CHANGED

android.intent.action.ACTION_TIMEZONE_CHANGED

时区该表

ACTION_BATTERY_LOW

android.intent.action.ACTION_BATTERY_LOW

电量低

ACTION_MEDIA_EJECT

android.intent.action.ACTION_MEDIA_EJECT

插入或拔出外部媒体

ACTION_MEDIA_BUTTON

android.intent.action.ACTION_MEDIA_BUTTON

按下媒体按钮

ACTION_PACKAGE_ADDED

android.intent.action.ACTION_PACKAGE_ADDED

添加包

ACTION_PACKAGE_REMOVED

android.intent.action.ACTION_PACKAGE_REMOVED

删除包

在这里，要练习3个内容

①自定义Broadcast Receiver

②Notification和NotificationManager的使用

③AlarmManager的使用

1、首先看一个自定义的广播事件的例子

Java代码

1. package org.hualang.broadcast;  
3. import android.app.Activity;  
4. import android.content.Intent;  
5. import android.os.Bundle;  
6. import android.view.View;  
7. import android.view.View.OnClickListener;  
8. import android.widget.Button;  
10. public class BroadCastTest extends Activity {  
11. /** Called when the activity is first created. */
12. private static final String MY_ACTION="org.hualang.broadcast.action.MY_ACTION";  
13. private Button btn;  
14. @Override
15. public void onCreate(Bundle savedInstanceState) {  
16. super.onCreate(savedInstanceState);  
17.         setContentView(R.layout.main);  
18.         btn=(Button)findViewById(R.id.button);  
19.         btn.setOnClickListener(new OnClickListener()  
20.         {  
22. @Override
23. public void onClick(View arg0) {  
24. // TODO Auto-generated method stub
25.                 Intent intent=new Intent();  
26.                 intent.setAction(MY_ACTION);  
27.                 intent.putExtra("msg", "同志们好！同志们辛苦啦！");  
28.                 sendBroadcast(intent);  
29.             }  
31.         });  
32.     }  
33. } 

package org.hualang.broadcast; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class BroadCastTest extends Activity { /** Called when the activity is first created. */ private static final String MY_ACTION="org.hualang.broadcast.action.MY_ACTION"; private Button btn; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btn=(Button)findViewById(R.id.button); btn.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent=new Intent(); intent.setAction(MY_ACTION); intent.putExtra("msg", "同志们好！同志们辛苦啦！"); sendBroadcast(intent); } }); } }

MyReceiver.java

Java代码

1. package org.hualang.broadcast;  
3. import android.content.BroadcastReceiver;  
4. import android.content.Context;  
5. import android.content.Intent;  
6. import android.widget.Toast;  
8. public class MyReceiver extends BroadcastReceiver {  
10. @Override
11. public void onReceive(Context arg0, Intent arg1) {  
12. // TODO Auto-generated method stub
13.         String msg=arg1.getStringExtra("msg");  
14.         Toast.makeText(arg0, msg, Toast.LENGTH_LONG).show();  
15.     }  
17. } 

package org.hualang.broadcast; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.widget.Toast; public class MyReceiver extends BroadcastReceiver { @Override public void onReceive(Context arg0, Intent arg1) { // TODO Auto-generated method stub String msg=arg1.getStringExtra("msg"); Toast.makeText(arg0, msg, Toast.LENGTH_LONG).show(); } }

注意：在AndroidManifest.xml文件中注册

Java代码

1. <receiver android:name="MyReceiver">  
2.             <intent-filter>  
3.                 <action android:name="org.hualang.broadcast.action.MY_ACTION"/>  
4.             </intent-filter>  
5.         </receiver> 

<receiver android:name="MyReceiver"> <intent-filter> <action android:name="org.hualang.broadcast.action.MY_ACTION"/> </intent-filter> </receiver>

我们还可以在AndroidManifest.xml文件中注销一个广播接收器，一般在Activity.onResume()方法中使用Context.registerReceiver()方法来注册一个广播接收器，在Activity.onPause()中使用unregisterReceiver(r)方法注销一个广播接收器，例如：

//实例化intent过滤器

IntentFilter filter = new IntentFilte()；

//实例化Receiver

MyReceiver r = new Receiver();

//注册Receiver

registerReceiver(r,filter);

为了注销一个BroadcastReceiver，应使用Context.unregisterReceiver方法，传入一个BroadcastReceiver实例

//注销

unregisterReceiver(r);

2、下面的是Notification的例子，比如手机来短信的时候，会在屏幕最上边有一个通知，那个就是Notification

DisplayActivity.java

Java代码

1. package org.hualang.notify;  
3. import android.app.Activity;  
4. import android.app.Notification;  
5. import android.app.NotificationManager;  
6. import android.app.PendingIntent;  
7. import android.content.Intent;  
8. import android.os.Bundle;  
9. import android.view.View;  
10. import android.view.View.OnClickListener;  
11. import android.widget.Button;  
13. public class DisplayActivity extends Activity {  
14. private Button cancelbtn;  
15. private Notification n;  
16. private NotificationManager nm;  
17. private static final int ID=1;  
18. public void onCreate(Bundle savedInstanceState)  
19.     {  
20. super.onCreate(savedInstanceState);  
21.         setContentView(R.layout.main2);  
22.         cancelbtn = (Button)findViewById(R.id.button2);  
23.         String service = NOTIFICATION_SERVICE;  
24.         nm = (NotificationManager)getSystemService(service);  
26.         n = new Notification();  
27. int icon = n.icon =R.drawable.icon;  
28.         String tickerText = "喜欢HTC的样子，喜欢defy的配置";  
29. long when = System.currentTimeMillis();  
30.         n.icon = icon;  
31.         n.tickerText = tickerText;  
32.         n.when = when;  
34.         Intent intent = new Intent(this,NotifyTest2.class);  
35.         PendingIntent pi = PendingIntent.getActivity(this, 0 , intent , 0);  
36.         n.setLatestEventInfo(this, "My Title", "My Content", pi);  
37.         nm.notify(ID, n);  
38.         cancelbtn.setOnClickListener(cancelListener);  
39.     }  
40. private OnClickListener cancelListener=new OnClickListener()  
41.     {  
42. public void onClick(View v)  
43.         {  
44.             nm.cancel(ID);  
45.         }  
46.     };  
47. } 

package org.hualang.notify; import android.app.Activity; import android.app.Notification; import android.app.NotificationManager; 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; public class DisplayActivity extends Activity { private Button cancelbtn; private Notification n; private NotificationManager nm; private static final int ID=1; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main2); cancelbtn = (Button)findViewById(R.id.button2); String service = NOTIFICATION_SERVICE; nm = (NotificationManager)getSystemService(service); n = new Notification(); int icon = n.icon =R.drawable.icon; String tickerText = "喜欢HTC的样子，喜欢defy的配置"; long when = System.currentTimeMillis(); n.icon = icon; n.tickerText = tickerText; n.when = when; Intent intent = new Intent(this,NotifyTest2.class); PendingIntent pi = PendingIntent.getActivity(this, 0 , intent , 0); n.setLatestEventInfo(this, "My Title", "My Content", pi); nm.notify(ID, n); cancelbtn.setOnClickListener(cancelListener); } private OnClickListener cancelListener=new OnClickListener() { public void onClick(View v) { nm.cancel(ID); } }; }

MyReceiver.java

Java代码

1. package org.hualang.notify;  
3. import android.content.BroadcastReceiver;  
4. import android.content.Context;  
5. import android.content.Intent;  
7. public class MyReceiver extends BroadcastReceiver {  
9. @Override
10. public void onReceive(Context context, Intent intent) {  
11. // TODO Auto-generated method stub
12.         Intent i=new Intent();  
13.         i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
14.         i.setClass(context,DisplayActivity.class);  
15.         context.startActivity(i);  
16.     }  
18. } 

package org.hualang.notify; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class MyReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub Intent i=new Intent(); i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); i.setClass(context,DisplayActivity.class); context.startActivity(i); } }

NotifyTest2.java

Java代码

1. package org.hualang.notify;  
3. import android.app.Activity;  
4. import android.content.Intent;  
5. import android.os.Bundle;  
6. import android.view.View;  
7. import android.view.View.OnClickListener;  
8. import android.widget.Button;  
10. public class NotifyTest2 extends Activity {  
11. /** Called when the activity is first created. */
12. private Button btn;  
13. private static final String MY_ACTION="org.hualang.notify.aciton.MY_ACITON";  
14. @Override
15. public void onCreate(Bundle savedInstanceState) {  
16. super.onCreate(savedInstanceState);  
17.         setContentView(R.layout.main);  
18.         btn=(Button)findViewById(R.id.button);  
19.         btn.setOnClickListener(listener);  
20.     }  
21. private OnClickListener listener=new OnClickListener()  
22.     {  
23. public void onClick(View v)  
24.         {  
25.             Intent intent=new Intent();  
26.             intent.setAction(MY_ACTION);  
27.             sendBroadcast(intent);  
28.         }  
29.     };  
30. } 

package org.hualang.notify; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class NotifyTest2 extends Activity { /** Called when the activity is first created. */ private Button btn; private static final String MY_ACTION="org.hualang.notify.aciton.MY_ACITON"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btn=(Button)findViewById(R.id.button); btn.setOnClickListener(listener); } private OnClickListener listener=new OnClickListener() { public void onClick(View v) { Intent intent=new Intent(); intent.setAction(MY_ACTION); sendBroadcast(intent); } }; }

注册AndroidManifest.xml

Java代码

1. <receiver android:name="MyReceiver">  
2.             <intent-filter>  
3.                 <action android:name="org.hualang.notify.aciton.MY_ACITON"/>  
4.             </intent-filter>  
5.         </receiver>  
6.         <activity android:name="DisplayActivity">  
7.         </activity> 

<receiver android:name="MyReceiver"> <intent-filter> <action android:name="org.hualang.notify.aciton.MY_ACITON"/> </intent-filter> </receiver> <activity android:name="DisplayActivity"> </activity>

运行结果如下：

3、下面是AlarmManager的例子，它是一个闹钟，感兴趣的朋友可以自己写一个小闹钟

AlarmManager常用的属性和方法

属性或方法名称

说明

ELAPSED_REALTIME

设置闹钟时间，从系统启动开始

ELAPSED_REALTIME_WAKEUP

设置闹钟时间，从系统启动开始，如火设备休眠则唤醒

INTERVAL_DAY

设置闹钟时间，间隔一天

INTERVAL_FIFTEEN_MINUTES

间隔15分钟

INTERVAL_HALF_DAY

间隔半天

INTERVAL_HALF_HOUR

间隔半小时

INTERVAL_HOUR

间隔1小时

RTC

设置闹钟时间，从系统当前时间开始(System.currentTimeMillis())

RTC_WAKEUP

设置闹钟时间，从系统当前时间开始，设备休眠则唤醒

set(int type,long tiggerAtTime,PendingIntent operation)

设置在某个时间执行闹钟

setRepeating(int type,long triggerAtTiem,long interval,PendingIntent operation)

设置在某个时间重复执行闹钟

setInexactRepeating(int type,long triggerAtTiem,long interval,PendingIntent operation)

是指在某个时间重复执行闹钟，但不是间隔固定时间

AlarmTest.java

Java代码

1. package org.hualang.alarm;  
3. import android.app.Activity;  
4. import android.app.AlarmManager;  
5. import android.app.PendingIntent;  
6. import android.content.Intent;  
7. import android.os.Bundle;  
8. import android.util.Log;  
9. import android.view.View;  
10. import android.view.View.OnClickListener;  
11. import android.widget.Button;  
13. public class AlarmTest extends Activity {  
14. /** Called when the activity is first created. */
15. private Button btn1,btn2;  
16. private static final String BC_ACTION="org.hualang.alarm.action.BC_ACTION";  
17. @Override
18. public void onCreate(Bundle savedInstanceState) {  
19. super.onCreate(savedInstanceState);  
20.         setContentView(R.layout.main);  
21.         btn1 = (Button)findViewById(R.id.button1);  
22.         btn2 = (Button)findViewById(R.id.button2);  
24. final AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);  
25.         Intent intent = new Intent();  
26.         intent.setAction(BC_ACTION);  
27.         intent.putExtra("msg", "你该起床了");  
28. final PendingIntent pi = PendingIntent.getBroadcast(AlarmTest.this, 0, intent, 0);  
29. final long time = System.currentTimeMillis();  
32.         btn1.setOnClickListener(new OnClickListener()  
33.         {  
34. public void onClick(View v)  
35.             {  
37.                 am.setRepeating(AlarmManager.RTC_WAKEUP, time, 5*1000, pi);  
38.             }  
39.         });  
40.         btn2.setOnClickListener(new OnClickListener()  
41.         {  
42. public void onClick(View v)  
43.             {  
44.                 am.cancel(pi);  
45.             }  
46.         });  
47.     }  
48. } 

package org.hualang.alarm; import android.app.Activity; import android.app.AlarmManager; import android.app.PendingIntent; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class AlarmTest extends Activity { /** Called when the activity is first created. */ private Button btn1,btn2; private static final String BC_ACTION="org.hualang.alarm.action.BC_ACTION"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btn1 = (Button)findViewById(R.id.button1); btn2 = (Button)findViewById(R.id.button2); final AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE); Intent intent = new Intent(); intent.setAction(BC_ACTION); intent.putExtra("msg", "你该起床了"); final PendingIntent pi = PendingIntent.getBroadcast(AlarmTest.this, 0, intent, 0); final long time = System.currentTimeMillis(); btn1.setOnClickListener(new OnClickListener() { public void onClick(View v) { am.setRepeating(AlarmManager.RTC_WAKEUP, time, 5*1000, pi); } }); btn2.setOnClickListener(new OnClickListener() { public void onClick(View v) { am.cancel(pi); } }); } }

MyReceiver.java

Java代码

1. package org.hualang.alarm;  
3. import android.content.BroadcastReceiver;  
4. import android.content.Context;  
5. import android.content.Intent;  
6. import android.util.Log;  
7. import android.widget.Toast;  
9. public class MyReceiver extends BroadcastReceiver {  
11. @Override
12. public void onReceive(Context context, Intent intent) {  
13. // TODO Auto-generated method stub
14.         String msg=intent.getStringExtra("msg");  
15.         Log.v("SERVICE","QIAN----------------------");  
16.         Toast.makeText(context, msg, Toast.LENGTH_LONG).show();  
17.         Log.v("SERVICE", "HOU-----------------------");  
18.     }  
20. } 

package org.hualang.alarm; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.util.Log; import android.widget.Toast; public class MyReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub String msg=intent.getStringExtra("msg"); Log.v("SERVICE","QIAN----------------------"); Toast.makeText(context, msg, Toast.LENGTH_LONG).show(); Log.v("SERVICE", "HOU-----------------------"); } }

注册AndroidManifest.xml

Java代码

1. <receiver android:name="MyReceiver">  
2.             <intent-filter>  
3.                 <action android:name="org.hualang.alarm.action.BC_ACTION"/>  
4.             </intent-filter>  
5.         </receiver> 

<receiver android:name="MyReceiver"> <intent-filter> <action android:name="org.hualang.alarm.action.BC_ACTION"/> </intent-filter> </receiver>

运行结果：

点击设置闹钟后，会每隔5秒弹出一个Toast，点击取消闹钟就不会弹出了