Short answer: they all run on the same thread. If instantiated from an Activity lifecycle callback, they all run on the main UI thread. Long answer: A thread may have a Looper, which contains a MessageQueue. In order to use this facility, you would have to create a Looper on the current thread by calling … Read more
You can use: Handler handler = new Handler() handler.postDelayed(new Runnable()) Or you can use: handler.removeCallbacksAndMessages(null); Docs public final void removeCallbacksAndMessages (Object token) Added in API level 1 Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed. Or you could also … Read more
You’re almost using postDelayed(Runnable, long) correctly, but just not quite. Let’s take a look at your Runnable. final Runnable r = new Runnable() { public void run() { handler.postDelayed(this, 1000); gameOver(); } }; When we call r.run(); the first thing it’s going to do is tell your handler to run the very same Runnable after … Read more
If whatever you are doing is “heavy” you should be doing it in a Thread. If you do not explicitly start it in its own thread, then it will run on the main (UI) thread which may be noticeable as jittery or slow to respond interface by your users. Interestingly when you are using a … Read more
In my experience calling this worked great! handler.removeCallbacksAndMessages(null); In the docs for removeCallbacksAndMessages it says… Remove any pending posts of callbacks and sent messages whose obj is token. If token is null, all callbacks and messages will be removed.
Only the parameterless constructor is deprecated, it is now preferred that you specify the Looper in the constructor via the Looper.getMainLooper() method. Use it for Java new Handler(Looper.getMainLooper()).postDelayed(new Runnable() { @Override public void run() { // Your Code } }, 3000); Use it for Kotlin Handler(Looper.getMainLooper()).postDelayed({ // Your Code }, 3000)
NOTE: This answer has gotten so much attention, that I need to update it. Since the original answer was posted, the comment from @dzeikei has gotten almost as much attention as the original answer. So here are 2 possible solutions: 1. If your background thread has a reference to a Context object: Make sure that … Read more
If IncomingHandler class is not static, it will have a reference to your Service object. Handler objects for the same thread all share a common Looper object, which they post messages to and read from. As messages contain target Handler, as long as there are messages with target handler in the message queue, the handler … Read more
Here is a real life example where HandlerThread becomes handy. When you register for Camera preview frames, you receive them in onPreviewFrame() callback. The documentation explains that This callback is invoked on the event thread open(int) was called from. Usually, this means that the callback will be invoked on the main (UI) thread. Thus, the … Read more
Thread: You can use the new Thread for long-running background tasks without impacting UI Thread. From java Thread, you can’t update UI Thread. Since normal Thread is not much useful for Android architecture, helper classes for threading have been introduced. You can find answers to your queries in Threading performance documentation page. Handler: A Handler … Read more