App shuts down once I navigate to the Fragment with RecyclerView and ViewModel It's was first time using ViewModel and I was following this [tutorial][1] What I want is for RecyclerView to display a LiveData that is retrieved from Room database Once I navigate to the Fragment I get this error: E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.plantmanagement, PID: 8767 java.lang.ClassCastException: com.example.plantmanagement.activity.MainActivity cannot be cast to com.example.plantmanagement.PlantApplication at...

viewModelFactory property has not been initialized in RecyclerView So I have an error that says viewModelFactory has not been initialized I tried to search other solutions but it didn't work. I want to populate data from Room Database and display it on the RecyclerView. class Edit_Form : Fragment() { lateinit var photoAdapter: Photo_Adapter var dataList = mutableListOf() private var layoutManager: RecyclerView.LayoutManager? = null private lateinit var adapter: RecyclerView.Adapter override fun onCreate(savedInstanceState: Bundle?) {...

kotlin/java match a number in a string with a regular For example, if I have these strings, is there any way I can get 123 of all these strings, or 777 or 888? https://www.example.com/any/123/ and https://www.example.com/any/777/123/ and https://www.example.com/any/777/123/888 What I mean is how to match the first or second or the third last number in the string.

Recycler view data not loading on screen I'm trying to show the recycler view's data on my app. The thing is, even though the NetworkStatus is successful (I can tell because I don't get the toast's message and the loader disappears and I can also see the data in the logcat), the info is not displayed. I am not sure if the error is in the way I'm calling the recycler view on my MainActivity or in the RecyclerAdapter but any idea as to where the problem is would be very helpful. This is the RecyclerAdapter: import...

How do I restore the previous RecyclerView state when a fragment is recreated? I have a Fragment in my Android app that has a RecyclerView and I want to restore the RecyclerView it previously had from the last time the user opened the app. In my Fragment I have the following blocks of code for saving and restoring the RecyclerView. private val LIST_STATE_KEY = "recycler_state" private var recyclerViewState : Parcelable? = null private lateinit var recyclerView: RecyclerView override fun onSaveInstanceState(outState: Bundle) { super.onSaveInstanceState(outState)...

How to keep onItemSelected on the same item selected after closing the app in Kotlin? i am translating an app in Kotlin and the user have the choice to choose between two different languages i created new Activity: @Suppress("DEPRECATION") class Languages_Activity : AppCompatActivity() { lateinit var spinner: Spinner lateinit var locale: Locale var back_btn: LinearLayout? = null private var currentLanguage = "en" private var currentLang: String? = null override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState)...

Should view binding properties in fragments should always have a backing non-nullable property? I've been reading https://developer.android.com/topic/libraries/view-binding and was thinking about how they define their view binding property in a fragment. This is the sample code: private var _binding: ResultProfileBinding? = null // This property is only valid between onCreateView and // onDestroyView. private val binding get() = _binding!! override fun onCreateView( inflater:...

Android Espresso. Test views that place in ViewGroup I have an LinearLayout, in which I add and remove view programmatically. But I add not a particularly view, instead I add ConstraintLayout with other view, that I need to test. So here in ConstaintLayout places EditText, which I want to test, type and check values, rest EditText. But I don't know how to get EditText with Espresso. I supposed that should work like this: @Test fun basicConverting() { onView( allOf( withParent(withId(R.id.convertingViewList)),...

Android studio unable to recognise kotlin keywords? Trying to set up an Open Source project (https://github.com/duckduckgo/Android), however after doing a gradle sync and everything when I access certain kotlin files, it isn't able to resolve the kotlin keywords ( by lazy, reified, etc.). Any ideas to why this is happening ? (Using an M1 Mac OS->Big Sur)

Business and Customer app in a single project in Kotlin Multiplatform? I am making an app that connects customers and businesses. Now I'd like to pack it into a single project as they are thematically connected and might share some of the logic. This would be simple enough with a native app but for multiplatform I am unsure as how to have them organized. Eg I'd have two IOS and two Android modules, but for the shared code, I'd need 3 shared libraries, sharedBussiness, sharedCustomer and common. Would this seperation be too difficult to handle when it comes to...

Load slider just once when user enters app How Binance's slider work? so that it would not load again when you swipe between items in the menu at the bottom of the page And it loads only the first time users enters the app.

How to access a complicated instance variable in kotlin I'm pretty new to Kotlin, and have no idea how to assign value for complicated variables. Given I'm in a class, I need to do some validations on this content variable. class MyClass( // other variables val content: Content, ) This Content object is another data class, which contains two other variables. One of them, the contents variable, is a list of another data class called ContentItem. As you can see below. data class Content( val contentType: ContentType, val contents:...

cannot cast another viewholder in same adapter I try to see three type of view in one recyclerview. but when i attach another viewholder, it warn error. java.lang.ClassCastException: kr.co.softcampus.solution.adapter.TestAdapter$ViewHolderClass cannot be cast to kr.co.softcampus.solution.adapter.TestAdapter$ViewHolderClass2 class TestAdapter( private val owner : AppCompatActivity, private val list: List, private val listconsult : List, private val listexpert : List, private val listcompany : List, var text:String = "" ) :...

CryptoJS.AES.encrypt giving different result in android (kotlin) Android client needs to use the same encryption which is used in our other Javascript application. i.e. val msg = "64 character long string" val key = "32 character long string" val iv = "32 character long string" const encrypted = CryptoJS.AES.encrypt(msg, key, { keySize: 16, iv, mode: CryptoJS.mode.CBC, padding: CryptoJS.pad.Pkcs7 }); I tried using the following in Kotlin //1. Create a cipher object val cipher = Cipher.getInstance("AES/CBC/PKCS7Padding") //2....

Is there a way to define an implicit ctor for a Kotlin class? as the title says it, is there any way to define a constructor or convertion for a class/object that can be called implicitly like this? class Person { val name: String val mood: Mood = Mood.Happy fun toString(): String = "$name is $mood" } fun main() { // Calls the magic implicit ctor val steve: Person = "Steve" // Prints "Steve is happy" println("$steve") }

With AlertDialog, how to align to top of the choices text with the checkbox? I am using setMultiChoiceItems of AlertDialog. The check mark is at the vertical center of the choice text. I would like it to be at the top. How to do that? (Kotlin code. Java answers will be fine.) AlertDialog.Builder (this).run { val choices = arrayOf( "Option 1 is very long. It is more than 3 lines. I would like to align the text top with the check box top.", "Option 2 is very long. It is more than 3 lines. I would like to align the text...

How to get walking turn-by-turn Directions in MapsActivity using Google Directions API on a route with multiple waypoints in Kotlin I have a map with user's current location and a route drawn with multiple waypoints and I want to navigate the user to walk on the drawn route, give him turn-by-turn directions in my map activity. I use Google directions API to draw the route. Important: I don't want to launch google maps, I want the directions in my app. One of the most important features of my app is that, when the user gets close to a marker the Marker InfoWindow will show up displaying some information from firebase about...

Kotlin flow WhileSubscribed I am studying Kotlin flows on Android and some of its behavior seems strange to me. The WhileSubscribed strategy does not always work as expected. For example: private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate) val instantFlow = flow { while (true) { emit(Instant.now()) delay(Duration.ofMinutes(1).toMillis()) } } .onStart { Log.d(TAG, "instantFlow -start") }...

How can i show RTF json into android textview or webview I have a C# desktop app where I input rich text in windows form and the exported data is like the following {\\rtf1\\ansi\\ansicpg1252\\deff0\\deflang1033{\\fonttbl{\\f0\\fnil\\fcharset0 Microsoft Sans Serif;}}\n\\viewkind4\\uc1\\pard\\f0\\fs17 Hello how are you dear?\\par\n} I want to show the rich text into my android app using eighter kotlin or java. Please help me. Your help is highly appreciated.

Takeing Screenshots in Service - Android I want to make a smart android overlay that blurs all faces on screen, To do so, I need to take a screenshot fast from the service class. I tried this: Process process; process = Runtime.getRuntime().exec("input keyevent 120"); but it didn't work, and I assume this answer will be too slow, I tried to use media projection from this <a...

Can't get data from firebase firestore in release mode android I can't get data from firestore. What is issue? Thank you very much! my data class:

data class User(
   val name: String,
   val phoneNumber: String,
   val timestamp: Timestamp,
   val status: Boolean,
   val inApp: String ) {
   constructor() : this("", "", Timestamp.now(), false, "") }

my ultils class: `class Constants { companion object { const val TOAST_ERROR = "Bạn cần nhập đúng số điện thoại để thực hiện yêu cầu này!" const val USERS = "Users" const val...

Unable to get the button of the alert dialog to prevent the dialog from closing in Kotlin I wanted to create an alert dialog that won't close on hitting its positiveButton. I modified my code as per many tutorials I found online. But I am not able to get the button, builder.getButton. val builder = AlertDialog.Builder(this) with(builder) { setTitle("Hello....?") setCancelable(false) setPositiveButton("Done", null) setNegativeButton("Cancel", null) show() val positiveButton: Button = builder.getButton(AlertDialog.BUTTON_POSITIVE)...

Attempt to invoke virtual method on a null object reference kotlin [duplicate] I was learing how to create Forecast App from this tutorial on yt: https://www.youtube.com/playlist?list=PLB6lc7nQ1n4jTLDyU2muTBo8xk0dg0D_w I did all from the tutorial with the weatherstack api and this works but weatherstack is no longer able to get future weather so i decided to change the api to weatherapi. And there is a problem, i have everything same except ApiService,...

How can I mock a constructor using mockito I have a method which creates an object of a class in local scope. I just want to mock this constructor (Items) using mockito Junit4. private fun getUploadItems(context: Context, hash: String): Items { val uploadItems: Items = Items(context, APPLICATION_ID) uploadItems.add(JsonObject().apply { addProperty("image", hash) addProperty("record_id", sCloudRecordId) addProperty(timeStampColumnName, System.currentTimeMillis()) })...

Compose navigation back button is not showing I am trying to set up the navigation back button following this SO thread, but can't make it work. @ExperimentalFoundationApi @Composable fun LazyVerticalGridActivityScreen() { val navController = rememberNavController() val navigationIcon: (@Composable () -> Unit)? = if (navController.previousBackStackEntry != null) { { IconButton(onClick...

Unresolved reference: bookInfoList Here is my full code of DashboardFragment.kt file How can I fix the error in (bookInfoList) The error part is bolded class DashboardFragment : Fragment() { lateinit var recyclerDashboard: RecyclerView lateinit var layoutManager: RecyclerView.LayoutManager lateinit var btnCheckInternet: Button lateinit var recyclerAdapter: DashboardRecyclerAdapter override fun onCreateView( inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle? ): View? { // Inflate the...

webview stuck in loading android studio - kotlin Hi, my webview stuck in this page when i click on one of the items. in the website it work correctly but in the webview it get stuck. private fun start_webview(theURL: String) { webView.apply { loadUrl(theURL) settings.javaScriptEnabled = true settings.allowContentAccess = true } webView.webChromeClient = WebChromeClient() webView.webViewClient...

how to fix an error message ( unresolved reference ) using kotlin i've just strated learning the basics of the Kotlin to create Android apps but i didn't understand why i cannot run my program althrough i'm following a tutorial

Unresolved reference: createWithAdaptiveBitmapContentUri I build sample project and got this issues with Kotlin https://github.com/android/user-interface-samples/tree/main/People

Kotlin local function with generic I'm just fooling around with some Functional Programming techniques and tried to implement a generic drop function for a list. However it seems the types are getting shadowed. I'm wondering why I can't re-use a generic type declared. The IDE doesn't want me to reuse the generic type sealed class List { companion object { fun <A> drop(n: Int): List<A> { fun go(n: Int, l: List<A>): List<A> = when (n) { 0 -> l else -> go(n - 1, l.tail())...