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This article mainly introduces "how to achieve multithreading in the background in Android". In daily operation, I believe that many people have doubts about how to achieve multithreading in the background in Android. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the doubt of "how to achieve multithreading in the background in Android". Next, please follow the editor to study!

Background function is one of the four major components of Android, its importance is self-evident, and service is the solution to realize the background running of programs in Android, which is very suitable for performing tasks that do not require interaction and have to run for a long time. By default, all tasks are completed in the main thread, that is, if we do not have multithreaded programming, it will cause the main thread to be blocked.

Multithreading

New Thread (new Runnable () {@ Override public void run () {}}) .start ()

New threads can be created through new Thread

Class MyThread1 implement Runnable {@ Override public void run () {}} new Thread (new MyThread ()) .start ()

By implementing the Runnable interface

Class MyThread1 extends Thread {@ Override public void run () {}} newMyThread.start ()

By inheriting Thread

Update UI when using multithreading:

RunOnUiThread (new Runnable () {public void run () {textView.setText (result);}})

Of course, Android also provides a set of asynchronous message handling mechanisms:

Public class MainActivity extends AppCompatActivity {private Handler handler=new Handler () {@ Override public void handleMessage (Message msg) {TextView textView= (TextView) findViewById (R.id.tvMsg); textView.setText (msg.obj.toString ());}}; @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_main) Button button= (Button) findViewById (R.id.button); button.setOnClickListener (new View.OnClickListener () {@ Override public void onClick (View v) {new Thread (new Runnable () {@ Override public void run () {Message message=new Message ()) Message.obj=new String (data); handler.sendMessage (message);}}) .start ();}});}}

Among them

Message is used to encapsulate messages.

Handle is used to send and process messages, calling sendMessage in child threads to send messages, and processing in HandleMessage in the main program

MessageQueu, which saves messages sent by handle waiting to be processed

Looper completes the message dispatch task, constantly checks whether there are any messages in the queue, and if so, extracts them to handle.

AsyncTask

Is an abstract class provided by Android simplified thread data update UI

OnPreExecute (): called before asynchronous execution starts

OnPostExecute (): called after the end of asynchronous execution

OnProgressUpdate

DoInBackground

Use servic

Start the service through startService, start it if there is no service, create it, call oncreat when you create it, and call onStartCommand every time startService is called

Through stopService or stopSelf, onDestroy is executed

Bind service

Use bindService to bind services

UnbindService unbinds

At this point, the study on "how to implement multithreading in the background in Android" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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