I have a weird problem. My android app runs fine I can open other programs and then reopen my app and it has no problem. When i touch the battery icon it closes and it resets all of my data. Does anyone know whats going on?
The basic setup of my app is from this tutorial. I'm having some problems when the application leaves focus it seems to drop out and crash randomly.
After searching through my code I found that my UpdateThread for my custom surface view was not restoring itself properly. So it was pausing and then not copying its values to a new thread when the app got focus again.
Related
I have some problems to my app and I don't have any idea to fix that.
I open my app and use it for a while, then I let my app run in background which means I don't close it and use my phone do other things.
But when I want to use my app again, I found that my phone becomes very lag. When I click background app button to show which app is running in background, my app jumps to screen very lag, and when I want to click it or want to close it, it will very lag too, which means maybe my app make my phone become lag.
This situation only happen when I want to open my app again or I want to slide out my app to close it. When my app is running in background and I do other things, my phone will not lag.
I don't konw what happend to my app, can anyone tell me how can I check my app,
and know what happened that I can fixed it, thank you!
Check in your application code that you have not put a heavy task on onResume() method. If possible try to take that execution in appropriate life cycle method.
Put a break point on method which is call when the application got visible and try to find out that if any function is not taking much time to execution.
We have a (rather complicated) Qt application, with port to Android. It worked quite OK - until we started trying it on Android Pie.
Sometimes, either after start, or after return from background, application visually freezes - however, logging shows that UI thread is alive, it responds to taps, widgets receive paintEvent()'s and process them. But nothing changes on screen.
Hardware buttons like 'Back' also work - application is able to show 'Are you sure to exit?" message box and it works properly.
Also, you you try to go ot home screen and back to app - most of the time it unfreezes.
Actually, this behavior started on Android 8, but was resolve with a dirty hack - doing hide/show for main widget upon receiving applicationStateChange(Active). But it stopped working on Android 9.
I am completely out of ideas what could we do to produce such behavior, and how to fix that...
After a long and rather tedious debugging we finally narrowed it to a problem in Qt itself.
I've reported a bug: https://bugreports.qt.io/browse/QTBUG-76142
However, I don't know whether it was fixed in newer releases, since we stopped development of Android apps for now.
This is not an actual solution, but shares some ideas. I used QT 6.3 and the same hang/freeze problem occurred in qt android app (arm64-v8a / Qt widgets) after returning from background or after phone auto off when app is opened and after return to phone on. Another consequence is that after sending the app to background, I can't use Google chrome properly (I only tested this app, not other apps). What happened is that it's very slow and scrolling in Chrome doesn't work as usual.
I suppressed this problem with this trick (not a solution): i.e., before sending the QT app to the background, I triggered it to show a message box (from clicking a button) and let message box open. Now the Google Chrome app worked normally. And after dragging the QT app to the front and giving OK to the message box, I was able to use the application as usual. No hang/freeze problem.
Also I read an article from a link (https://lists.qt-project.org/pipermail/interest/2014-November/014218.html) : That is, we can able to modify the QtActivity.java (which can communicate to the QT app) and use the on pause and on resume event. So what I thought is that, If I trigger the app to show Qt message box from this "on pause" event, and automatically close the same in the "on resume" event this hang/freeze can be handled.
But I didn't try above (modify QtActivity.java) because now I switched to QT 6.4 and hang/freeze problem is not present in this version.
First off, this has never happened before on any other android device I've used (multiple devices have been tried and tested before this).
Now I have an app that I have worked on for a little over a year now, it is called AutomatedId (on the app store) and it has worked quite well for my company for quite some time.
Recently I have been given a device to add compatibility to the app (specifically for reading UHF tags) but that isn't the problem.
The problem comes whenever you open the app, the screen stops reading inputs completely, as well as buttons cease to function. I turned on developer options to see the screen inputs and as i suspected, it completely stops and does not read any of the inputs after the app is opened. Clicks don't work, buttons don't work, keyboard doesn't open, hardware buttons on the device stop working. It's a mess, does anyone know what could have caused this?
This is a S98 from here: http://www.wepoy.com/product_view_18.html
moved my comment to the answer as you said. This may be due to memory leak. Here are some references that may help you fix them: Fixing-Memory-Leaks-in-Android-Studio & use this library from square to detect memory leaks early: leakcanary
i have a Phonegap and JQM app.
Problem is, if I switch to another app and then back to my app, App is completely reloaded and start again.
Is posible this disable?
Thanks for any advice.
This is happening because there is a lack of memory for the app to run. So as soon as u go to home the app dies and on opening again it reloads the app from the start. To confirm that this is indeed happening i would suggest that you close all running apps on your phone and then run your app. Im sure it would run properly even after switching to home screen and coming back.I don't think its possible to get around this behavior. Design your app so that it has a small startup time so that its usable even on phones with less ram where such problems would come.
I have an Android app that works fine the first time you run it.
However, when you press HOME (so it pauses), and restart it from the home screen all I get is the music restarted.
I've not yet got to the stage of saving/restoring states yet (will do soon!).
It seems that the main update thread is not resuming.
It calls onRestart() fine...
I'm new to Java/Android so I apologize if this is a basic schoolboy error!
TIA for any advice
John
Programming applications for Android is a bit different then programming for conventional operating systems. Android stops your application when it looses focus. You'll have to read about activity lifecycle. If you're creating some kind of music player you should consider using a background service with a worker thread.