I have a MAUI app on Android which works perfectly when launched from Visual Studio with the debugger attached. If I published an APK and install it on the device manually, the application crashes as soon as I use the AppShell to change the current page.
How can I attach the debugger to it after I've launched it manually? Failing that, just finding a way to see a stack trace for the unhandled exception would be a big step forward.
I tried capturing a bug report and reproducing the crash, but the report did not appear to contain any account of crash. I was unable to find any crash dump logged by the OS, but this is my first Android app, so I might be missing something there.
Thank you #jan-joneš, you set me along the right path. Although it's outdated with respect to MAUI, I found a useful page in the Xamarin documentation with more tips.
It would be so much easier if these exceptions were flagged by the debugger!
Related
I remember to have seen that Android started to restart apps when these crash for the first time. But I can't find this statement in the documentation or release notes.
Do you know since which OS/SDK version this happen? Maybe I was dreaming?
I've tested with 4 different model devices and the behaviour seems to vary on device rather than android version.
Auto starting after a crash is not a standard behavior of Android. More commonly after an app crash, you are shown a dialog with an option to open the app again if you choose to do so. You can see the dialog in the following document.
Reference: https://developer.android.com/games/optimize/crash
Also, I think auto-restart of an app after a crash is not a good feature. If there is something wrong with the app causing a crash when you launch the app, then there is a good chance it may crash again with the auto relaunch. Why have the user see the crash again unnecessarily.
I just finished my last app and after intensive testing on android studio no bugs or errors pooped up.
But when I use my phone for some time and try to check my app it crashes, and error pops up.
Is there a way to find out the stack trace od that error? specially since its not connected to my PC.
You can integrate tools for analyse, like:
Crashlytics
So you have a dashboard and can setting a e-mail for warning.
You can use different options:
Store logcat file in Internal memory as txt file. This will be best solution since it will provide all the necessary information of pre-conditons for the crash
Implement crashanalytics like Hockeyapp
Use remote debugging. Refer this official document for more info
You can find more details for approach 1 & 2 at: remote logcat - Android Studio
I'm developing an app using Android Studio. Now I'm facing a bug where the app crashes when I do the following:
Press the home button.
Use the device for some 10 minutes (i.e. wait).
Run the app again. Crash!
There is no easier way to reproduce the crash (nothing in onResume). As you can imagine, this is kind of hard to debug. In an ideal world, the OS (Android 5.0) would let me send a bug report to myself. The app is not published yet, so I don't see how I could get hold of the crash dump. Is it saved somewhere on the device?
I did try to debug the app from Developer Options, using the wait for debugger setting and then attaching to the process from within Android Studio. This, however, seems to make the bug go away. (The app is probably restarted.)
Q: How do I find the cause of the crash given these circumstances?
My intuition tells me that you are using some 'static' variables/fields in your application.
When your app goes to background and it is not used, system could drop process (because of memory management) of this application from memory. When you come back, Application object and all application proces in system is recreated, so all static variables are cleared/reinitialized.
Am i right?
Try looking into your logcat and if that is not an option for you. try some crash analytic like the following.
https://mint.splunk.com/
Integrate it in your app just with a single line and whenever your app get crashed you will receive a mail of your crash logs..
it will easily help you to determine your crash scenario..
And just out of curiosity are you using any singlton class in your Activity.?
I found the crash using adb as described here. Never realized that logcat keeps logs from previous executions. Nice!
I have just started doing Android development on Mac OS X in Eclipse. When debugging an Activity, I keep getting the following errors:
The JAR file /platforms/android-10/android.jar has no source attachment.
This is starting to get very annoying, does it mean something is throwing an exception somewhere? (the message itself does not give any meaningful information as to why this is happening) I do not want to step into the source; does Eclipse do this by default? How do I disable it?
It looks like you have some error in your application. And Android subsystem throws exception. Normally, if such exception originates from android, you'll see this behavior.
What you should do:
Turn on LogCat view to see logs.
Launch your app without debugger (Ctrl+F11 on ubuntu/windows)
Inspect those logs in LogCat very carefully. They will contain the place where exception happened (originating from your code). You will then easily be able to fix the issue yourself (or ask for more assistance if needed).
In a normal development workflow you shouldn't hit cases like yours too often. Its just the learning curve :) So stay calm and keep learning.
Please note, unlike many other questions having the subject title "application has stopped unexpectedly", I am not asking for troubleshooting a particular problem.
Rather, I am asking for an outline of the best strategy for an Android/Eclipse/Java rookie to tackle this formidable task of digesting huge amounts of information in order to develop (and debug!) a simple Android application.
In my case, I took the sample skeleton app from the SDK, modified it slightly and what did I get the moment I try to run it?
The application
(process.com.example.android.skeletonapp)
has stopped unexpectedly. Please try
again.
OK, so I know that I have to look LogCat. It's full of timestamped lines staring at me... What do I do now? What do I need to look for?
Is there a way to single-step the program, to find the statement that makes the app crash? (I thought Java programs never crash, but apparently I was mistaken)
How do I place a breakpoint?
Can you recommend an Android debug tutorial online, other than this one?
I'm an Eclipse/Android beginner as well, but hopefully my simple debugging process can help...
You set breakpoints in Eclipse by right-clicking next to the line you want to break at and selecting "Toggle Breakpoint". From there you'll want to select "Debug" rather than the standard "Run", which will allow you to step through and so on. Use the filters provided by LogCat (referenced in your tutorial) so you can target the messages you want rather than wading through all the output. That will (hopefully) go a long way in helping you make sense of your errors.
As for other good tutorials, I was searching around for a few myself, but didn't manage to find any gems yet.
Filter your log to just Error and look for FATAL EXCEPTION
If you use the Logcat display inside the 'debug' perspective in Eclipse the lines are colour-coded. It's pretty easy to find what made your app crash because it's usually in red.
The Java (or Dalvik) virtual machine should never crash, but if your program throws an exception and does not catch it the VM will terminate your program, which is the 'crash' you are seeing.
Check whether your app has the needed permissions.I was also getting the same error and I checked the logcat debug log which showed this:
04-15 13:38:25.387: E/AndroidRuntime(694): java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:555-555-5555 cmp=com.android.phone/.OutgoingCallBroadcaster } from ProcessRecord{44068640 694:rahulserver.test/10055} (pid=694, uid=10055) requires android.permission.CALL_PHONE
I then gave the needed permission in my android-manifest which worked for me.
From the Home screen, press the Menu key.
List item
Touch Settings.
Touch Applications.
Touch Manage Applications.
Touch All.
Select the application that is having issues.
Touch Clear data and Clear cache if they are available. This resets the app as if it was new, and may delete personal data stored in the app.