Android之BroadcastReceiver(广播接受者)详解

xiaoxiao2021-03-25 105

广播接受者又称全局大喇叭

分为：标准广播、有序广播。标准广播：属于异步执行广播，广播发送出去以后广播接受器可以同时接收到，没有先后顺序工作效率无法拦截。有序广播：属于同步执行广播广播发出去只有一个广播接受器能接受这一条广播。接受完毕以后广播接受器可以选择拦截或者，继续传给下一个接受器，优先级高优先收到广播效率比较低。广播的两种注册方式静态：在清单文件中注册动态：在带代码中注册，必须onDestroy时取消注册

1 .网络状态监听广播

MainActivity.class

public class MainActivity extends BaseActivity { private IntentFilter filter; private NetWorkChangeReceiver receiver; @Override protected int bindLayout() {//加载布局文件 return R.layout.activity_main; } @Override protected void initView() {//初始化控件 filter = new IntentFilter();//创建意图过滤器 //添加网络变化的广播 filter.addAction("android.net.conn.CONNECTIVITY_CHANGE"); receiver = new NetWorkChangeReceiver();//创建广播监听器 registerReceiver(receiver, filter);//注册广播 } protected void onDestroy() { super.onDestroy(); unregisterReceiver(receiver);//解除注册 } //监听网络变化的广播 class NetWorkChangeReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { //判断网络连接还是没有连接 ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo(); if (networkInfo != null && networkInfo.isAvailable()) { Toast.makeText(MainActivity.this, "网络已连接", Toast.LENGTH_SHORT).show(); } else { Toast.makeText(MainActivity.this, "网络断开", Toast.LENGTH_SHORT).show(); } } } }

AndroidManifest.xml

2.标准广播

MainActivity.class

public class MainActivity extends BaseActivity { /*标准广播发送标准广播（开启另一个程序）步骤： 1.首先创建一个新项目 2.在新项目中创建广播接受器，在onReceive方法中 public void onReceive(Context context, Intent intent) { intent = new Intent(context,MainActivity.class); intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);//开启一个新栈 context.startActivity(intent); 3.在新项目清单中注册广播添加发送的广播频道 <action android:name="com.example.androidbroadcastreceiver.receiver.MyBroadcastReceiver" /> **在现在的程序中点击发送广播就能启动另一个程序了。** */ @Override protected int bindLayout() { return R.layout.activity_standard_broadcast_receiver; } public void standardBR(View view) { Intent intent = new Intent("com.example.androidbroadcastreceiver.receiver.MyBroadcastReceiver"); //intent.putExtra("广播", 2);//这里可以设置传值 sendBroadcast(intent); } }

3.有序广播

MainActivity.class

/*有序广播发送有序广播(优先级高的优先接收到广播) 3.设置优先级intent-filter android:priority="100" 优先级高的优先收到广播拦截（abortBroadcast()）以后广播终端 */ public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_order_broadcast_receiver); } public void orderBR(View view) {//打开有序广播 Intent intent = new Intent("com.example.androidbroadcastreceiver.receiver.MyBroadcastReceiver"); intent.putExtra("广播", 3); sendOrderedBroadcast(intent, null);//发送有序广播需要两个参数1.intent 2.权限参数设置为null } }

MyBroadcastReceiver.class

//广播接受器 public class MyBroadcastReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { if (intent.getIntExtra("广播", 0) == 3) { Toast.makeText(context, "发送有序广播(优先级高的优先接收到广播)\n" + "并且终止广播禁止程序启动", Toast.LENGTH_SHORT).show(); } abortBroadcast();//广播拦截，禁止向下传递 } }

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.androidbroadcastreceiver">  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />  <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=".receiver.MyBroadcastReceiver" android:enabled="true" android:exported="true">  <intent-filter android:priority="100"> <action android:name="com.example.androidbroadcastreceiver.receiver.MyBroadcastReceiver" /> </intent-filter> </receiver> </application> </manifest>

4.自定义广播

MainActivity.class

/* 自定义广播 */ public class MainActivity extends BaseActivity { @Override protected int bindLayout() { return R.layout.activity_custom_broadcast_receiver; } public void customBR(View view) {//打开自定义广播 Intent intent = new Intent("com.example.androidbroadcastreceiver.receiver.CustomBroadcastReceiver"); intent.putExtra("zdy", "自定义广播"); sendBroadcast(intent); } }

CustomBroadcastReceiver.class

/*自定义广播接受器步骤： 1.创建广播接受器是必须勾选enabled、exported，否者接受不到广播 android:enabled="true" android:exported="true" 2.创建Intent i= new Intent("发送的广播"); 可以传值i.putString("标记"，"值")； sendBroadcast(intent); 然后接受器就能就收到广播啦！ */ public class CustomBroadcastReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { Toast.makeText(context, intent.getStringExtra("zdy"), Toast.LENGTH_SHORT).show(); } }

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.androidbroadcastreceiver"> <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=".receiver.CustomBroadcastReceiver" android:enabled="true" android:exported="true"> <intent-filter> <action android:name="com.example.androidbroadcastreceiver.receiver.CustomBroadcastReceiver" /> </intent-filter> </receiver> </application> </manifest>

5.本地广播

LocalBroadcastReceiverActivity.class

/* 本地广播步骤： 1.首先创建LocalBroadcastManager对象管理广播、IntentFilter、LocalReceiver（广播接受器） 2.通过manager来注册、和解绑广播 3.本地广播只能在自身应用程序中使用，安全性高 */ public class LocalBroadcastReceiverActivity extends AppCompatActivity { private LocalBroadcastManager manager; private IntentFilter filter; private LocalReceiver receiver; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_local_broadcast_receiver); manager = LocalBroadcastManager.getInstance(this); filter = new IntentFilter(); filter.addAction("com.example.androidbroadcastreceiver.activity.LocalBroadcastReceiverActivity.LocalReceiver"); receiver = new LocalReceiver(); manager.registerReceiver(receiver, filter); } public void localBR(View view) {//打开本地广播安全不能跳转到别的程序 Intent intent = new Intent("com.example.androidbroadcastreceiver.activity.LocalBroadcastReceiverActivity.LocalReceiver"); intent.putExtra("bd", "我是刚创建的本地广播\n" + "不能走出这个应用程序"); manager.sendBroadcast(intent); } @Override protected void onDestroy() { super.onDestroy(); manager.unregisterReceiver(receiver); } class LocalReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { Toast.makeText(context, intent.getStringExtra("bd"), Toast.LENGTH_SHORT).show(); } } } End!

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