The technical principles of Android support the technical principles of the local broadcast manager of the library

The local radio manager in the Android support library is a tool class for broadcasting communication in the application.It provides a simple and efficient way to send and receive local broadcasts to achieve communication between components. Local broadcasting is an internal radio communication method. Unlike global broadcasting, local broadcasting can only be passed on to the same application and will not be received by other applications.This limitation makes local broadcasts more secure and more efficient, suitable for communication between components inside. The implementation principles of local broadcasting managers are as follows: 1. Registered broadcast receiver: The components in the application need to receive local broadcasts through a broadcast receiver.In components that need to be received, by calling the `LocalBroadCastManager.getInstance (context) .RegisterReceiver (Receiver, Filter) method to register the broadcast receiver.Among them, `Context` is the context object,` Receiver` is a broadcast receiver, and `Filter` is an IntentFilter object to specify which type of broadcast. 2. Send local broadcast: The components sent to the local broadcast by calling the `LocalBroadCastManager.getInstance (Context) .sendbroadcast (INTENT) method to send broadcast.Among them, `Context` is the context object, and` intent` is an Intent object that is used to specify the content of the broadcast. 3. Broadcast receiving processing: After sending a broadcast, the local broadcast manager will send the broadcast to all registered broadcast receivers.After receiving the broadcast, the broadcast receiver will execute the pre -defined processing logic. The technical principles of the local radio manager are as follows: 1. Single mode: Local broadcast manager uses a singles mode to ensure that there is only one local radio manager instance in the entire application.This can ensure that all radio receivers and transmitters use the same broadcast manager object to avoid data sharing between multiple instances. 2. Use the registry management Broadcast receiver: Local broadcast managers use a registry to manage registered broadcast receivers.When the broadcast is sent, the local broadcast manager finds a matching broadcast receiver from the registry and sends the broadcast to them.This method improves the efficiency of the broadcast sending and avoids the sending the broadcast to the invalid broadcast receiver. 3. Use the Handler mechanism: Local broadcast managers use the Handler mechanism to handle the process of broadcasting and receiving.When sending a broadcast, the local broadcast manager sends the broadcast to the main thread to execute through Handler to ensure that the processing logic of the broadcast is executed in the main thread.This can avoid thread security issues that occur during broadcasting. The following is a sample code using a local broadcast manager: First, register a radio receiver in the component of the receiving broadcast: BroadcastReceiver receiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { // Treat the receiving broadcast } }; IntentFilter filter = new IntentFilter("com.example.MY_ACTION"); LocalBroadcastManager.getInstance(context).registerReceiver(receiver, filter); Then, send a broadcast in the component of the radio: Intent intent = new Intent("com.example.MY_ACTION"); LocalBroadcastManager.getInstance(context).sendBroadcast(intent); By using a local broadcast manager, applications can easily achieve communication between components, improve the efficiency of broadcast sending and receiving, while ensuring the security and consistency of data.