当前位置： 代码迷 >> Android >> android播音事件机制及应用(实现简单的定时提醒功能) 转
  详细解决方案

android播音事件机制及应用(实现简单的定时提醒功能) 转

热度：32   发布时间：2016-05-01 20:48:36.0
android广播事件机制及应用(实现简单的定时提醒功能) 转

Android广播事件机制及应用(实现简单的定时提醒功能)

    博客分类：?
  • android 研发
?
涉及的主要内容：1) AlarmManager 和 PendingIntent 2) BroadReceiver 3) Notification and NotificationManager?

? 1.Android广播事件机制?
???? Android的广播事件处理类似于普通的事件处理。不同之处在于，后者是靠点击按钮这样的组件行为来触发，而前者是通过构建Intent对象，使用sentBroadcast()方法来发起一个系统级别的事件广播来传递信息。广播事件的接收是通过定义一个继承Broadcast Receiver的类实现的，继承该类后覆盖其onReceive()方法,在该方法中响应事件。Android系统中定义了很多标准的Broadcast Action来响应系统广播事件。例如：ACTION_TIME_CHANGED（时间改变时触发）。但是，我们也可以自己定义Broadcast Receiver接收广播事件。?
? 2.实现简单的定时提醒功能?
???? 主要包括三部分部分：?
???? 1） 定时 - 通过定义Activity发出广播?
???? 2） 接收广播 - 通过实现BroadcastReceiver接收广播?
???? 3)?? 提醒 - 并通过Notification提醒用户?
???? 现在我们来具体实现这三部分：?
???? 2.1 如何定时，从而发出广播呢？?
?????? 现在的手机都有闹钟的功能，我们可以利用系统提供的闹钟功能，来定时，即发出广播。具体地，在Android开发中可以用AlarmManager来实现。?
?????? AlarmManager 提供了一种系统级的提示服务，允许你安排在某个时间执行某一个服务。?
?????? AlarmManager的使用步骤说明如下：?
?????? 1）获得AlarmManager实例： AlarmManager对象一般不直接实例化，而是通过Context.getSystemService(Context.ALARM_SERVIECE) 方法获得?
?????? 2）定义一个PendingIntent来发出广播。?
?????? 3）调用AlarmManager的相关方法，设置定时、重复提醒等功能。?
?????? 详细代码如下(ReminderSetting.java)：?
Java代码??收藏代码
  1. package?com.Reminder;??
  2. import?java.util.Calendar;??
  3. ??
  4. import?android.app.Activity;??
  5. import?android.app.AlarmManager;??
  6. import?android.app.PendingIntent;??
  7. import?android.content.Intent;??
  8. import?android.os.Bundle;??
  9. import?android.view.View;??
  10. import?android.widget.Button;??
  11. ??
  12. /**?
  13. ?*?trigger?the?Broadcast?event?and?set?the?alarm?
  14. ?*/??
  15. public?class?ReminderSetting?extends?Activity?{??
  16. ??????
  17. ????Button?btnEnable;??
  18. ??????
  19. ????/**?Called?when?the?activity?is?first?created.?*/??
  20. ????@Override??
  21. ????public?void?onCreate(Bundle?savedInstanceState)?{??
  22. ????????super.onCreate(savedInstanceState);??
  23. ????????setContentView(R.layout.main);??
  24. ??????????
  25. ????????/*?create?a?button.?When?you?click?the?button,?the?alarm?clock?is?enabled?*/??
  26. ????????btnEnable=(Button)findViewById(R.id.btnEnable);??
  27. ????????btnEnable.setOnClickListener(new?View.OnClickListener()?{??
  28. ????????????@Override??
  29. ????????????public?void?onClick(View?v)?{??
  30. ????????????????setReminder(true);??
  31. ????????????}??
  32. ????????});??
  33. ????}??
  34. ??????
  35. ????/**?
  36. ?????*?Set?the?alarm??
  37. ?????*??
  38. [email protected]ot??
  39. ?????*/??
  40. ????private?void?setReminder(boolean?b)?{??
  41. ??????????
  42. ????????//?get?the?AlarmManager?instance???
  43. ????????AlarmManager?am=?(AlarmManager)?getSystemService(ALARM_SERVICE);??
  44. ????????//?create?a?PendingIntent?that?will?perform?a?broadcast??
  45. ????????PendingIntent?pi=?PendingIntent.getBroadcast(ReminderSetting.this,?0,?new?Intent(this,MyReceiver.class),?0);??
  46. ??????????
  47. ????????if(b){??
  48. ????????????//?just?use?current?time?as?the?Alarm?time.???
  49. ????????????Calendar?c=Calendar.getInstance();??
  50. ????????????//?schedule?an?alarm??
  51. ????????????am.set(AlarmManager.RTC_WAKEUP,?c.getTimeInMillis(),?pi);??
  52. ????????}??
  53. ????????else{??
  54. ????????????//?cancel?current?alarm??
  55. ????????????am.cancel(pi);??
  56. ????????}??
  57. ??????????
  58. ????}??
  59. }??

2.2 接收广播?
?????? 新建一个class 继承BroadcastReceiver，并实现onReceive()方法。当BroadcastReceiver接收到广播后，就会去执行OnReceive()方法。所以，我们在OnReceive()方法中加上代码，当接收到广播后就跳到显示提醒信息的Activity。具体代码如下( MyReceiver.java)：??
Java代码??收藏代码
  1. package?com.Reminder;??
  2. import?android.content.BroadcastReceiver;??
  3. import?android.content.Context;??
  4. import?android.content.Intent;??
  5. ??
  6. /**?
  7. ?*?Receive?the?broadcast?and?start?the?activity?that?will?show?the?alarm?
  8. ?*/??
  9. public?class?MyReceiver?extends?BroadcastReceiver?{??
  10. ??
  11. ????/**?
  12. ?????*?called?when?the?BroadcastReceiver?is?receiving?an?Intent?broadcast.?
  13. ?????*/??
  14. ????@Override??
  15. ????public?void?onReceive(Context?context,?Intent?intent)?{??
  16. ??????????
  17. ????????/*?start?another?activity?-?MyAlarm?to?display?the?alarm?*/??
  18. ????????intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);??
  19. ????????intent.setClass(context,?MyAlarm.class);??
  20. ????????context.startActivity(intent);??
  21. ??????????
  22. ????}??
  23. ??
  24. }??

注意：创建完BroadcastReceiver后，需要在AndroidManifest.xml中注册：?
<receiver android:name=".MyReceiver">?????
?????? <intent-filter>?
??????? <action android:name= "com.Reminder.MyReceiver" />?
??? </intent-filter>?
</receiver>?
2.3 提醒功能?
?????? 新建一个Activity，我们在这个Activity中通过Android的Notification对象来提醒用户。我们将添加提示音,一个TextView来显示提示内容和并一个button来取消提醒。?
????? 其中，创建Notification主要包括：?
?????? 1）获得系统级得服务NotificationManager，通过 Context.getSystemService(NOTIFICATION_SERVICE)获得。?
?????? 2）实例化Notification对象，并设置各种我们需要的属性，比如:设置声音。?
?????? 3）调用NotificationManager的notify()方法显示Notification?
????? 详细代码如下：MyAlarm.java?
Java代码??收藏代码
  1. package?com.Reminder;??
  2. import?android.app.Activity;??
  3. import?android.app.Notification;??
  4. import?android.app.NotificationManager;??
  5. import?android.net.Uri;??
  6. import?android.os.Bundle;??
  7. import?android.provider.MediaStore.Audio;??
  8. import?android.view.View;??
  9. import?android.widget.Button;??
  10. import?android.widget.TextView;??
  11. ??
  12. /**?
  13. ?*?Display?the?alarm?information??
  14. ?*/??
  15. public?class?MyAlarm?extends?Activity?{??
  16. ??
  17. ????/**?
  18. ?????*?An?identifier?for?this?notification?unique?within?your?application?
  19. ?????*/??
  20. ????public?static?final?int?NOTIFICATION_ID=1;???
  21. ??????
  22. ????@Override??
  23. ????protected?void?onCreate(Bundle?savedInstanceState)?{??
  24. ?????????super.onCreate(savedInstanceState);??
  25. ?????????setContentView(R.layout.my_alarm);??
  26. ??????????
  27. ????????//?create?the?instance?of?NotificationManager??
  28. ????????final?NotificationManager?nm=(NotificationManager)?getSystemService(NOTIFICATION_SERVICE);??
  29. ????????//?create?the?instance?of?Notification??
  30. ????????Notification?n=new?Notification();??
  31. ????????/*?set?the?sound?of?the?alarm.?There?are?two?way?of?setting?the?sound?*/??
  32. ??????????//?n.sound=Uri.parse("file:///sdcard/alarm.mp3");??
  33. ????????n.sound=Uri.withAppendedPath(Audio.Media.INTERNAL_CONTENT_URI,?"20");??
  34. ????????//?Post?a?notification?to?be?shown?in?the?status?bar??
  35. ????????nm.notify(NOTIFICATION_ID,?n);??
  36. ??????????
  37. ????????/*?display?some?information?*/??
  38. ????????TextView?tv=(TextView)findViewById(R.id.tvNotification);??
  39. ????????tv.setText("Hello,?it's?time?to?bla?bla...");??
  40. ??????????
  41. ????????/*?the?button?by?which?you?can?cancel?the?alarm?*/??
  42. ????????Button?btnCancel=(Button)findViewById(R.id.btnCancel);??
  43. ????????btnCancel.setOnClickListener(new?View.OnClickListener()?{??
  44. ??????????????
  45. ????????????@Override??
  46. ????????????public?void?onClick(View?arg0)?{??
  47. ????????????????nm.cancel(NOTIFICATION_ID);??
  48. ????????????????finish();??
  49. ????????????}??
  50. ????????});??
  51. ????}??
  52. ??????
  53. }??

注：关于提示音设置（Notification.sound），可以参考：http://developer.android.com/guide/topics/ui/notifiers/notifications.html?中的相关部分。
  相关解决方案

代码迷 - 您身边的软件异常，代码异常，编程异常助手（发现，解决，分享）
Copyright © 2009-2013 DAIMAMI.COM. All rights reserved.