can I use async do IO in one activity, and bind th...

# android

[Ifvwm]

can I use async do IO in one activity, and bind that Deferred object into a companion object, in another activity to do await for the IO result to update UI?

[Andrew]

You would have to wait for the result of your async task before moving forward.

[Andrew]

Actually, can you describe what your end goal is?

[Joost Klitsie]

It sounds to me like yes you can but no you shouldn't. This would be abusing static fields leading to leaks most likely.

[Jeremy]

You may want to look at either using a Service or WorkManager

[Joost Klitsie]

Or use single activity architecture and share your viewmodel

[Scott Kruse]

companion object is undoubtedly not the right approach

[Ifvwm]

for example, there're MainActivity and SecondActivity, from MainActivity jump to SecondActivity, and SecondActivity do some IO and UI, but those IO take time too long, so I wonder if I can do IO in MainActivity with async, then get result with await in SecondActivity?

[Ifvwm]

I have tried that, but when I use await I got "parent job is cancelling" exception

[Ifvwm]

this is the code, and it does not have that problem anymore, weird, but it worked now.
https://paste.ubuntu.com/p/pVwqQmDRJy/

[Joost Klitsie]

Well it is still the wrong way of doing thigs. You are trying to do asynchronous work on UI level, which is a bad practice. There are amazing components and architectural patterns that can help you, but part of that is to actually learn to develop properly for Android. I advise to check out the Android code labs by google to get a hang of different topics, Workmanager is one of them (which might suit your needs here)
https://developer.android.com/courses start with android basics and when you get the hang of it continue with the advanced android in kotlin.