Android深入四大组件（四）广播的注册、发送和接收过程.docVIP

Android深入四大组件（四）广播的注册、发送和接收过程 1.广播的注册过程 BroadcastReceiver的注册分为两种，分别是静态注册和动态注册，静态注册在应用安装时由PackageManagerService来完成注册过程，关于这一过程，我会在后续的介绍PackageManagerService文章中详细介绍。这里只介绍BroadcastReceiver的动态注册。 要想动态注册BroadcastReceiver，需要调用registerReceiver方法，它的实现在ContextWrapper中，代码如下所示。 frameworks/base/core/Java/android/content/ContextWrapper.java Override public Intent registerReceiver( BroadcastReceiver receiver, IntentFilter filter) { return mBase.registerReceiver(receiver, filter); } ContextImpl的registerReceiver方法有很多重载的方法最终会调用registerReceiverInternal方法： frameworks/base/core/java/android/app/ContextImpl.java private Intent registerReceiverInternal(BroadcastReceiver receiver, int userId, IntentFilter filter, String broadcastPermission, Handler scheduler, Context context) { IIntentReceiver rd = null; if (receiver != null) { if (mPackageInfo != null context != null) {//1 if (scheduler == null) { scheduler = mMainThread.getHandler(); } rd = mPackageInfo.getReceiverDispatcher( receiver, context, scheduler, mMainThread.getInstrumentation(), true);//2 } else { if (scheduler == null) { scheduler = mMainThread.getHandler(); } rd = new LoadedApk.ReceiverDispatcher( receiver, context, scheduler, null, true).getIIntentReceiver();//3 } } try { final Intent intent = ActivityManagerNative.getDefault().registerReceiver( mMainThread.getApplicationThread(), mBasePackageName, rd, filter, broadcastPermission, userId);//4 if (intent != null) { intent.setExtrasClassLoader(getClassLoader()); intent.prepareToEnterProcess(); } return intent; } catch (RemoteException e) {