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Questions tagged [android-handler]

A Handler allows you to send and process `Message` and Runnable objects associated with a thread's `MessageQueue`. Each Handler instance is associated with a single thread and that thread's message queue. When you create a new Handler, it is bound to the thread / message queue of the thread that is creating it -- from that point on, it will deliver messages and runnables to that message queue and execute them as they come out of the message queue.

A Handler allows you to send and process Message and Runnable objects associated with a thread's MessageQueue. Each Handler instance is associated with a single thread and that thread's message queue. When you create a new Handler, it is bound to the thread / message queue of the thread that is creating it -- from that point on, it will deliver messages and runnables to that message queue and execute them as they come out of the message queue.

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Handler vs AsyncTask vs Thread

I got slightly confused about the differences between Handlers, AsyncTask and Threads in Android. I've read quite a few blogs and questions here in StackOverflow. Handler are background threads that provide you to communicate with the UI. Updating…
Alx
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Running code in main thread from another thread

In an android service I have created thread(s) for doing some background task. I have a situation where a thread needs to post certain task on main thread's message queue, for example a Runnable. Is there a way to get Handler of the main thread and…
Ahmed
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What do I use now that Handler() is deprecated?

How do I fix the deprecation warning in this code? Alternatively, are there any other options for doing this? Handler().postDelayed({ context?.let { //code } }, 3000)
Bolt UIX
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This Handler class should be static or leaks might occur: IncomingHandler

I'm developing an Android 2.3.3 application with a service. I have this inside that service to communicate with Main activity: public class UDPListenerService extends Service { private static final String TAG = "UDPListenerService"; …
VansFannel
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cancelling a handler.postdelayed process

I am using handler.postDelayed() to create a waiting period before the next stage of my app takes place. During the wait period I am displaying a dialog with progress bar and cancel button. My problem is I can't find a way to cancel the postDelayed…
Ron
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How to remove all callbacks from a Handler?

I have a Handler from my sub-Activity that was called by the main Activity. This Handler is used by sub-classes to postDelay some Runnables, and I can't manage them. Now, in the onStop event, I need to remove them before finishing the Activity…
Luke Vo
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Android: When should I use a Handler() and when should I use a Thread?

When I need something to run asynchronously, such as a long running task or a logic that uses the network, or for whatever reason, Starting a new Thread and running it works fine. Creating a Handler and running it works as well. What's the…
JRun
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Stop handler.postDelayed()

I call multiple Handlers by new Handler().postDelayed(new Runnable()..... How can I stop it when I click on back? public class MyActivity extends AppCompatActivity implements OnClickListener { private Button btn; private Handler handler; …
basti12354
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Handler is abstract ,cannot be instantiated

I am trying to use a Handler in my app. However, when I instantiate it like this: Handler handler = new Handler(); I get the following error: Gradle: error: Handler is abstract; cannot be instantiated And when I check the solutions, it asks me to…
Chinmay Dabke
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When to use handler.post() & when to new Thread()

I'm wondering when should I use handler.post(runnable); and when should I use new Thread(runnable).start(); It is mentioned in developers documentation for Handler: Causes the Runnable r to be added to the message queue. The runnable will be run…
reiley
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Best use of HandlerThread over other similar classes

I am trying to understand the best use case of using HandlerThread. As per definition: "Handy class for starting a new thread that has a looper. The looper can then be used to create handler classes. Note that start() must still be called." I may…
Androidme
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How to use postDelayed() correctly in Android Studio?

I have a countDownTimer and if the user does not hit the gameButton within the 12th second I want the gameOver method called. The problem is that either the game function instantly gets called when the countDownTimer is 12 or the timer just keeps…
Ryder Thacker
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Job Scheduler vs Background Service

I have an app which has a feature A which should run in background every minute. Feature A is that the app should connect to a database, read some data then get the current location of the device and based on them check a condition, if the condition…
Code Pope
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How to stop Handler Runnable?

I am using a handler in the following program and I want to stop it when i=5 but the handler doesn't stop and run continuously. b1.setOnClickListener(new OnClickListener() { public void onClick(View v) { handler = new…
user2745636
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Handlers, MessageQueue, Looper, do they all run on the UI thread?

I'm trying to wrap my head around threading, and I know that I may use a Handler to post messages/runnables to the MessageQueue, which in turn gets picked up by the Looper and sent back to the Handler for processing. If I post to a Handler in my…
rogerkk
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