四大应用组件之BroadcastReceiver【Android】

一.理论概述

1. 广播事件处理属于系统级的事件处理(一般事件处理是属于View级的事件处理)
2. 一个应用可以在发生特定事件时发送Broadcast, 系统中任何应用只要注册了对应Receiver就会接收到此Broadcast
3. 一个应用如果对某个广播感兴趣, 就可以注册对应的Receiver来接收广播
4. 广播事件机制是应用程序(进程间)之间通信的一种手段

二.相关API

Context

sendBroadcast(Intent intent) : 发送一般广播

sendOrderedBroadcast(Intent intent) : 发送有序广播

registerReceiver(receiver, intentFilter) : 注册广播接收器

unRegisterReceiver(receiver) : 解注册广播接收器

BroadcastReceiver

onReceive(Context context, Intent intent) : 接收到广播的回调

abortBroadcast() : 中断广播的继续传播

boolean isOrderedBroadcast() : 判断是否是有序广播

常见系统广播：

收到短信广播 : android.provider.Telephony.SMS_RECEIVED

开机完成广播 : Intent.ACTION_BOOT_COMPLETED

应用被卸载广播 : Intent.ACTION_PACKAGE_REMOVED

手机锁屏 : Intent.ACTION_SCREEN_OFF

手机开屏 : Intent.ACTION_SCREEN_ON

三.代码实现：

1.编写广播接收器类 

package com.example.boardreceiver;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * 静态注册的receiver * @author Xiaocici * */public class MyReceiver1 extends BroadcastReceiver {public MyReceiver1() {Log.e("TAG", "MyReceiver1()");}@Overridepublic void onReceive(Context context, Intent intent) {String action = intent.getStringExtra("action");Log.e("TAG","MyReceiver1 onReceive()" + action);}}

package com.example.boardreceiver;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * 动态注册的receiver * @author Xiaocici * */public class MyReceiver2 extends BroadcastReceiver {public MyReceiver2() {Log.e("TAG", "MyReceiver2()");}@Overridepublic void onReceive(Context context, Intent intent) {String action = intent.getStringExtra("action");Log.e("TAG","MyReceiver2 onReceive()" + action);}}

2.注册广播接收器

方式一: 配置文件注册(静态注册)

<span style="white-space:pre"></span><receiver android:name="com.atguigu.t6_br.MyBroadcastReceiver">            <!--priority指定当前receiver的优先级, 值是0-1000, 越大越好  -->            <intent-filter android:priority="500">                <action android:name="com.atguigu.t6_br.mybroadcastreceiver"/>            </intent-filter>        </receiver>

例：

        <receiver android:name="com.example.boardreceiver.MyReceiver1">            <intent-filter >                <action android:name="com.example.boardreceiver.MyReceiver1.action"/>            </intent-filter>        </receiver>

方式二: 硬编码注册(动态注册)

MyBroadcastReceiver2 receiver2 = new MyBroadcastReceiver2();IntentFilter filter = new IntentFilter(action);registerReceiver(receiver2, filter);

例：

package com.example.boardreceiver;import android.app.Activity;import android.content.IntentFilter;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Toast;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);}private MyReceiver2 receiver;/* * 注册广播接收器 */public void registBR(View v) {if (receiver == null) {// 创建Receiver对象receiver = new MyReceiver2();// 创建过滤器对象IntentFilter filter = new IntentFilter("com.example.boardreceiver.MyReceiver1.action");// 注册ReceiverregisterReceiver(receiver, filter);Toast.makeText(this, "注册广播接收器", 0).show();} else {Toast.makeText(this, "已经注册了广播接收器", 0).show();}}/* * 解注册广播接收器 */public void unRegistBR(View v) {if (receiver != null) {unregisterReceiver(receiver);receiver = null;Toast.makeText(this, "解注册广播接收器", 0).show();} else {Toast.makeText(this, "还未注册广播接收器", 0).show();}}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();if (receiver != null) {unregisterReceiver(receiver);receiver = null;}}}

3.发送广播

一般广播：

//发送一般广播public void sendNormalBC(View v){Intent intent = new Intent("com.example.boardreceiver.MyReceiver1.action");intent.putExtra("action", "benben");sendBroadcast(intent );Toast.makeText(this, "发送一般广播", 0).show();}

有序广播：

//发送有序广播public void sendOrderBC(View v){Intent intent = new Intent("com.example.boardreceiver.MyReceiver.action2");intent.putExtra("action", "chacha");sendOrderedBroadcast(intent, null);Toast.makeText(this, "发送有序广播", 0).show();}

有序广播的注册：

        <receiver android:name="com.example.boardreceiver.MyReceiver3">            <intent-filter android:priority="1000">                <action android:name="com.example.boardreceiver.MyReceiver.action2"/>            </intent-filter>        </receiver>                <receiver android:name="com.example.boardreceiver.MyReceiver4">            <intent-filter android:priority="2147483647">//优先级                <action android:name="com.example.boardreceiver.MyReceiver.action2"/>            </intent-filter>        </receiver>

如果需中断广播：

package com.example.boardreceiver;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;/** * 静态注册的receiver *  * @author Xiaocici * */public class MyReceiver4 extends BroadcastReceiver {public MyReceiver4() {Log.e("TAG", "MyReceiver4()");}@Overridepublic void onReceive(Context context, Intent intent) {String action = intent.getStringExtra("action");Log.e("TAG", "MyReceiver4 onReceive()" + action);if (isOrderedBroadcast()) { abortBroadcast();//中断广播}}}