Generated apk crashes out

Question

I've just finished my last android project but I'm facing a weird problem. All the time I was working on the app, I used to run it on my device by clicking that green button and it worked fine. But now that I've created my app's apk file, it installes on device with no problem, but at the time I want to start the app, it crashes out and never starts.

Any help will be appreciated. Thanks.

UPDATE: Dependencies:

implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.2'
implementation 'com.android.support:support-vector-drawable:26.1.0'
implementation 'com.android.support:preference-v14:26.1.0'
implementation 'com.github.codekidX:storage-chooser:2.0.4.2'
implementation 'com.google.firebase:firebase-storage:16.0.1'
implementation 'com.google.firebase:firebase-auth:16.0.3'
implementation 'com.google.firebase:firebase-core:16.0.1'
implementation 'android.arch.lifecycle:viewmodel:1.1.1'
implementation 'android.arch.lifecycle:extensions:1.1.1'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
implementation 'com.android.support:cardview-v7:26.1.0'

ViewModel Class:

private class MyImageViewModel: ViewModel(){
    fun returnImagePath(): String{
        return createdImageFile
        //createdImageFile is a global string that contains the path of an image and its default value is ""
    }
}

ViewModelUsage:

val model = ViewModelProviders.of(this).get(MyImageViewModel::class.java)
    createdImageFile = model.returnImagePath()
    if (createdImageFile != ""){
        //do sth with the image file path
    }

Connect phone to laptop and open android studio, then launch the app installed on phone and check what logcat has to say and post here. — Ümañg ßürmån, Aug 28 '18 at 17:26
@UmangBurman I'm using ViewModel in my app. logcat says Cannot create an instance of the ViewModel class — Soroush, Aug 28 '18 at 17:32
Can you post your dependencies please. Edit your question and paste it. Also paste the activity class in which app crashes.. — Ümañg ßürmån, Aug 28 '18 at 17:58
@Robert Thanks for your comment but it didn't solve the problem — Soroush, Aug 28 '18 at 18:09
@UmangBurman My question is if sth is wrong with view model, why does it work when the app is started by android studio? — Soroush, Aug 28 '18 at 18:10
I'm posting a solution. try that. and update me. okay. This is in kotlin, but I did it in java in my iMac — Ümañg ßürmån, Aug 28 '18 at 18:11
@Soroush Just curious do you have Proguard enabled? Maybe it is stripping out something in release builds that is needed to create ViewModel. — Shobhit Puri, Aug 28 '18 at 18:18
@ShobhitPuri I have but I disabled it and tried again. Nothing changed — Soroush, Aug 28 '18 at 18:21
just a min, i'll try myself in kotlin and see what is the problem.. — Ümañg ßürmån, Aug 28 '18 at 18:29
@UmangBurman Thanks for the time you spent dude. Look at my answer — Soroush, Aug 28 '18 at 18:56

score 0 · Answer 1 · answered Aug 28 '18 at 18:13

0

Solution:

Instead of:

val model = ViewModelProviders.of(this).get(MyImageViewModel::class.java)

write:

var model: MyImageViewModel()

then,

model = ViewModelProviders.of(this).get(MyImageViewModel::class.java)

Try it, Hopefully it should work.

answered Aug 28 '18 at 18:13

Ümañg ßürmån

9,695
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Sorry nothing changed – Soroush Aug 28 '18 at 18:27
@Soroush Sorry, but I had no such errors.. Infact I used your code, your dependency, everything. App works fine. My device Moto X Play. I made the apk, copied in internal storage, installed opened fine. – Ümañg ßürmån Aug 28 '18 at 18:47
@Soroush Try this: "'implementation 'android.arch.lifecycle:viewmodel:1.1.1' -ktx implementation 'android.arch.lifecycle:extensions:1.1.1' -ktx" – Ümañg ßürmån Aug 28 '18 at 18:51

score 0 · Accepted Answer · answered Aug 28 '18 at 18:55

0

Thanks to everyone who tried to help, I found the problem. It is a little stupid thing. ViewModel class should not be private! That's it.

answered Aug 28 '18 at 18:55

Soroush

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Great... How did it work in my device? can you answer that dude? – Ümañg ßürmån Aug 28 '18 at 18:59
Well, Congrats that it worked, but I don't think that initialization depends on private or public. Anyway happy coding. – Ümañg ßürmån Aug 28 '18 at 19:02
@UmangBurman No I have seen this in other topics too. like https://stackoverflow.com/a/50969087/10245431 – Soroush Aug 28 '18 at 19:30
Oh, Okay, may be I implemented public class then in my app.. I did not notice i guess. – Ümañg ßürmån Aug 28 '18 at 19:35

Generated apk crashes out

2 Answers2