标签:android广播注册和发送 sendbroadcast broadcastreceiver
在Android应用程序框架中,Activity和Service类都继承了ContextWrapper类,因此,我们可以在Activity或者Service的子类中调用registerReceiver函数来注册广播接收器。
下图是在activity中注册广播的过程:
step1~step3,就是一般的调用过程。
step4,registerReceiverInternal()方法如下:
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) { if (scheduler == null) { scheduler = mMainThread.getHandler(); } rd = mPackageInfo.getReceiverDispatcher( receiver, context, scheduler, mMainThread.getInstrumentation(), true); } else { if (scheduler == null) { scheduler = mMainThread.getHandler(); } rd = new LoadedApk.ReceiverDispatcher( receiver, context, scheduler, null, true).getIIntentReceiver(); } } try { return ActivityManagerNative.getDefault().registerReceiver( mMainThread.getApplicationThread(), mBasePackageName, rd, filter, broadcastPermission, userId); } catch (RemoteException e) { return null; } }
step6,先从已有的注册列表mReceivers中查找是否由相同的ReceiverDispatcher,若之前没有注册过,则new一个ReceiverDispatcher,并记录在mReceivers中,ReceiverDispatcher创建过程中,同时生成一个InnerReceiver,InnerReceiver用于接收处理sendBroadcast发过来的广播。
step9~step11,通过binder访问ActivityManagerService的registerReceiver,将广播接收器receiver保存起来。
下图是广播发送(sendBroadcast)的过程:
分析步骤参考:http://blog.csdn.net/luoshengyang/article/details/6744448
右键复制图片地址,在浏览器中打开即可查看大图。
未完待续,有不对的地方,请指正。
Android4.4 framework分析——广播的注册(BroadcastReceiver)和发送(sendbroadcast)过程分析
标签:android广播注册和发送 sendbroadcast broadcastreceiver
原文地址:http://blog.csdn.net/canghai1129/article/details/41019137