I was trying to update the recycler view content from a background thread in Kotlin. I am not using AsyncTask.
Here is my code, i want to know if there is any better way than this:
In my MainActivity, i have progressThread as a member variable.
var progressThread = Thread()
Then in my method where i want to run the thread first i am defining it...like
progressThread = Thread (
Runnable {
kotlin.run {
try {
while (i <= 100 && !progressThread.isInterrupted) {
Thread.sleep(200)
//Some Logic
runOnUiThread {
//this runs in ui thread
}
i++
}
}catch (e:InterruptedException){
progressThread.interrupt()
}
}
})
after that i am starting it in the same method as
progressThread.start()
and for stopping it, i have a listener to cancel the progress and in the callback of that listener, i have written:
progressThread.interrupt()
In this case, to update the UI from a background thread, you can create a handler attached to the UI thread, and then post an action as a Runnable : Handler handler = new Handler(Looper. getMainLooper()); handler. post(new Runnable() { @Override public void run() { // update the ui from here } });
You can use runOnUiThread() method of activity to update UI from background thread. Or you can use a android Handler to achieve this.
If you put long running work on the UI thread, you can get ANR errors. If you have multiple threads and put long running work on the non-UI threads, those non-UI threads can't inform the user of what is happening.
Android App Development for Beginners Android AsyncTask going to do background operation on background thread and update on main thread. In android we cant directly touch background thread to main thread in android development. asynctask help us to make communication between background thread to main thread.
Updated
Coroutines are stable now,: https://kotlinlang.org/docs/reference/coroutines-overview.html
Old Answer
Yes, you can do this using doAsync
from kotlin anko library that is fairly simple and easy to use.
add following line in module level gradle file:
compile "org.jetbrains.anko:anko-commons:0.10.0"
Code example:
val future = doAsync {
// do your background thread task
result = someTask()
uiThread {
// use result here if you want to update ui
updateUI(result)
}
}
code block written in uiThread
will only be executed if your Activity or Fragment is in foreground mode (It is lifecycle aware). So if you are trying to stop thread because you don't want your ui code to execute when Activity is in background, then this is an ideal case for you.
As you can check doAsync
returns a Future object so you can cancel the background task, by cancel()
function:
future.cancel(true)
pass true
if you want to stop the thread even when it has started executing.
If you have more specialised case to handle stopping case then you can do the same thing as in your example.
You can use Kotlin Coroutines also but its in Experimental phase, still you can try it out: https://kotlinlang.org/docs/reference/coroutines.html
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