`I have an error on:
``
package com.example.movietime
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.movietime.databinding.ActivityRegisterBinding
import com.google.firebase.ktx.Firebase
class RegisterActivity : AppCompatActivity() {
DatabaseReference database = FirebaseDatabase.getInstance().getReference(); // also here with all sentence
// binding
private lateinit var binding: ActivityRegisterBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityRegisterBinding.inflate(layoutInflater)
setContentView(binding.root)
// move to login after click
binding.submitButton.setOnClickListener {
startActivity(Intent(this, LoginActiivty::class.java))
}
}
}
building grade(:app)
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'com.google.gms.google-services'
}
android {
namespace 'com.example.movietime'
compileSdk 33
defaultConfig {
applicationId "com.example.movietime"
minSdk 21
targetSdk 33
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildFeatures {
viewBinding true
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation 'com.google.firebase:firebase-database-ktx'
implementation 'androidx.core:core-ktx:1.9.0'
implementation 'androidx.appcompat:appcompat:1.5.1'
implementation 'com.google.android.material:material:1.7.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation platform('com.google.firebase:firebase-bom:30.0.1')
implementation 'com.google.firebase:firebase-analytics-ktx'
implementation 'com.google.firebase:firebase-auth-ktx'
implementation 'com.google.firebase:firebase-firestore-ktx'
implementation 'com.google.firebase:firebase-firestore'
implementation platform('com.google.firebase:firebase-bom:31.0.2')
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}
build grade(project)
buildscript {
repositories {
// Check that you have the following line (if not, add it):
google() // Google's Maven repository
}
dependencies {
classpath 'com.android.tools.build:gradle:7.3.1'
classpath 'com.google.gms:google-services:4.3.14'
}
}
// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
id 'com.android.application' version '7.3.1' apply false
id 'com.android.library' version '7.3.1' apply false
id 'org.jetbrains.kotlin.android' version '1.7.20' apply false
}
``
`I'm kind of lost already,
tried this
Unresolved reference:database for Firebase Realtime database in my Kotlin program
but it didnt help either.
any suggestion will be welcome!
Unresolved reference:database for Firebase Realtime database in my Kotlin program
Reconnection the firebase to project and import from begging.`
I actually answered that question but in your case, the problem isn't related to the import but to the name of the class. So you're getting the following error:
Unsolved reference: Databaserefernce
Because there is no class that is called Databaserefernce but DatabaseReference. See the capital R? To solve this, please change the type of the variable to DatabaseReference, add the corresponding import and the error will go away.
Besides that, the way you're initializing the variable is not correct. That's how you do it in Java. In Kotlin you should do it like this:
val db = FirebaseDatabase.getInstance().reference
Related
I am trying to use Firebase Realtime database in Kotlin.
I have followed this tutorial but I think that something is wrong, because I get an error before compiling when I want to retrieve an instance of the database (Unresolved reference DataBasereference (or database if I uncomment the first line of the function tryToRead).
This is the code:
MainActivity.kt
package com.example.spesapp
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.google.firebase.ktx.Firebase
class MainActivity : AppCompatActivity() {
private lateinit var database: DataBasereference //Here I see "Unresolved reference"
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
}
fun tryToRead(){
//val database = Firebase.database
val myref = database.getReference
}
}
Gradle (module level)
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'com.google.gms.google-services'
}
android {
compileSdk 32
defaultConfig {
applicationId "com.example.frangelapp"
minSdk 21
targetSdk 32
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.4.1'
implementation 'com.google.android.material:material:1.5.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
implementation platform('com.google.firebase:firebase-bom:30.0.1')
implementation 'com.google.firebase:firebase-analytics-ktx'
implementation 'com.google.firebase:firebase-auth-ktx'
implementation 'com.google.firebase:firebase-firestore-ktx'
implementation 'com.google.firebase:firebase-firestore'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}
Gradle (Project level)
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
// Check that you have the following line (if not, add it):
google() // Google's Maven repository
}
dependencies {
// Add this line
classpath 'com.google.gms:google-services:4.3.10'
}
}
plugins {
id 'com.android.application' version '7.1.1' apply false
id 'com.android.library' version '7.1.1' apply false
id 'org.jetbrains.kotlin.android' version '1.6.10' apply false
}
task clean(type: Delete) {
delete rootProject.buildDir
}
I don't know what is the error. The tutorial seemed to be very easy, but I am facing with this problem.
Thanks in advance
You get the following error:
Unresolved reference DataBasereference
Because you have not added the Realtime Database dependency in your project. To solve this, simply add:
implementation 'com.google.firebase:firebase-database-ktx'
Inside your build.gradle file.
After going through documentations and trying solutions of similar questions here on stackoverflow, nothing seems to fix the issue.
I tried altering all related dependencies, trying additional dependencies and tweaking the versions. Gradle builds successfully but there is a runtime error that through trial and error, the only method I found that could fix it was removing the argument from the ViewModel which is not desirable for me as the same setup used to work in my older projects.
RuntimeException
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example, PID: 17527
java.lang.RuntimeException: Cannot create an instance of class com.example.ui.MainViewModel
at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:188)
build.gradle(:app)
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'kotlin-kapt'
id 'dagger.hilt.android.plugin'
id 'com.google.devtools.ksp' version '1.6.10-1.0.2'
}
kotlin {
sourceSets {
debug {
kotlin.srcDir("build/generated/ksp/debug/kotlin")
}
release {
kotlin.srcDir("build/generated/ksp/release/kotlin")
}
}
}
android {
compileSdk 31
defaultConfig {
multiDexEnabled = true
applicationId "com.example"
minSdk 23
targetSdk 31
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
vectorDrawables {
useSupportLibrary true
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
coreLibraryDesugaringEnabled true
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
freeCompilerArgs += '-Xopt-in=kotlin.RequiresOptIn'
}
buildFeatures {
compose true
}
composeOptions {
kotlinCompilerExtensionVersion compose_version
}
packagingOptions {
resources {
excludes += '/META-INF/{AL2.0,LGPL2.1}'
}
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation "androidx.compose.ui:ui:$compose_version"
implementation 'androidx.compose.material3:material3:1.0.0-alpha04'
implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.4.0'
implementation 'androidx.activity:activity-compose:1.4.0'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
debugImplementation "androidx.compose.ui:ui-test-manifest:$compose_version"
//lifecycle
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.4.0"
implementation "androidx.lifecycle:lifecycle-viewmodel-compose:2.4.0"
//Hilt
implementation "com.google.dagger:hilt-android:$hilt_version"
kapt "com.google.dagger:hilt-compiler:$hilt_version"
implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03"
kapt "androidx.hilt:hilt-compiler:1.0.0"
//Coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0'
//DataStore
implementation "androidx.datastore:datastore-preferences:1.0.0"
//Desugaring
coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.5'
//Compose Destinations
implementation "io.github.raamcosta.compose-destinations:core:1.2.1-beta"
ksp "io.github.raamcosta.compose-destinations:ksp:1.2.1-beta"
build.gradle(Project)
buildscript {
ext {
compose_version = '1.2.0-alpha02'
hilt_version = "2.40.5"
}
dependencies {
classpath "com.google.dagger:hilt-android-gradle-plugin:$hilt_version"
}
}// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
id 'com.android.application' version '7.2.0-beta01' apply false
id 'com.android.library' version '7.2.0-beta01' apply false
id 'org.jetbrains.kotlin.android' version '1.6.10' apply false
id 'org.jetbrains.kotlin.jvm' version '1.6.10' apply false
}
task clean(type: Delete) {
delete rootProject.buildDir
}
MainViewModel.kt
#HiltViewModel
class MainViewModel #Inject constructor(
private val dataStoreRepository: DataStoreRepository
) : ViewModel() {...}
MainActivity.kt
#AndroidEntryPoint
class MainActivity : ComponentActivity() {
private val mainViewModel: MainViewModel by viewModels()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
DestinationsNavHost(navGraph = NavGraphs.root)
}
}
}
Did you create module class? like below:
#Module
#InstallIn(SingletonComponent::class)
class RepositoryModule {
#Provides
#Singleton
fun provideDataStoreRepository(): DataStoreRepository = DataStoreRepository()
}
I am trying to call a suspend function using viewModelScope.launch in which "launch" is showing as Unresolved reference.
Here is build.gradle
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.example.mynotes"
minSdk 27
targetSdk 31
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
packagingOptions {
exclude 'META-INF/atomicfu.kotlin_module'
}
}
dependencies {
implementation "androidx.appcompat:appcompat:$rootProject.appCompatVersion"
implementation "androidx.activity:activity-ktx:$rootProject.activityVersion"
// Dependencies for working with Architecture components
// You'll probably have to update the version numbers in build.gradle (Project)
// Room components
implementation "androidx.room:room-ktx:$rootProject.roomVersion"
kapt "androidx.room:room-compiler:$rootProject.roomVersion"
androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"
// Lifecycle components
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$rootProject.lifecycleVersion"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$rootProject.lifecycleVersion"
implementation "androidx.lifecycle:lifecycle-common-java8:$rootProject.lifecycleVersion"
// Kotlin components
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
api "org.jetbrains.kotlinx:kotlinx-coroutines-core:$rootProject.coroutines"
api "org.jetbrains.kotlinx:kotlinx-coroutines-android:$rootProject.coroutines"
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0'
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0'
// UI
implementation "androidx.constraintlayout:constraintlayout:$rootProject.constraintLayoutVersion"
implementation "com.google.android.material:material:$rootProject.materialVersion"
// Testing
testImplementation "junit:junit:$rootProject.junitVersion"
androidTestImplementation "androidx.arch.core:core-testing:$rootProject.coreTestingVersion"
androidTestImplementation ("androidx.test.espresso:espresso-core:$rootProject.espressoVersion", {
exclude group: 'com.android.support', module: 'support-annotations'
})
androidTestImplementation "androidx.test.ext:junit:$rootProject.androidxJunitVersion"
}
and the ViewModel.kt
package com.example.mynotes
import android.app.Application
//import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.LiveData
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.*
class NotesViewModel(application: Application) : ViewModel() {
private val repository : NotesRepository
val allNotes : LiveData<List<Notes>>
init {
val dao = NotesDatabase.getDatabase(application).getNotesDao()
repository = NotesRepository(dao)
allNotes = repository.allNotes
}
fun deleteNotes(notes: Notes) = viewModelScope.launch(Dispatchers.IO) {
repository.delete(notes)
}
}
In the function deleteNotes "viewModelScope.launch" is showing Unresolved reference: launch but there is no error while building the app but my app crash while running.
I think it's because of the way you are declaring the variable, since you are declaring it as a direct function, you can try the following:
fun deleteNotes(notes: Notes) {
viewModelScope.launch(Dispatchers.IO) {
repository.delete(notes)
}
}
It's possible the issue is related that when the method is declared and stored in memory, the scope hasnt been assigned yet.
Which version are you using?
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.1"
Try to use this case is different.
Try to invalide cache and restart if still not recognized
I get a strange runtime exception when running some very simple code (8-line method; only 2 lines relevant) on my Android 10 device, after compiling with Android Studio Canary 7 (or 6) using Jetpack Compose alpha12.
Error:
java.lang.NoSuchMethodError: No static method copy-0d7_KjU$default(JFFFFILjava/lang/Object;)J in class Landroidx/compose/ui/graphics/Color; or its super classes (declaration of 'androidx.compose.ui.graphics.Color' appears in /data/app/com.example.myapplication-GbQdisqKhWdQawA6_DsPkQ==/base.apk)
at com.example.myapplication.MainActivity.onCreate(MainActivity.kt:15)
at android.app.Activity.performCreate(Activity.java:7955)
Code:
package com.example.myapplication
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.activity.compose.setContent
import androidx.compose.ui.graphics.Color
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val x = Color(0xFFBB86FC)
val y = x.copy() // ******* line 15 *******
setContent {
Surface(color = MaterialTheme.colors.background) {
Text(text = "hello world")
}
}
}
}
Top-level build.gradle:
buildscript {
ext {
compose_version = '1.0.0-alpha12'
}
repositories {
google()
jcenter()
}
dependencies {
classpath "com.android.tools.build:gradle:7.0.0-alpha07"
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.30-RC"
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
Module level build.gradle:
plugins {
id 'com.android.application'
id 'kotlin-android'
}
android {
compileSdkVersion 30
buildToolsVersion "30.0.3"
defaultConfig {
applicationId "com.example.myapplication"
minSdkVersion 29
targetSdkVersion 30
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
useIR = true
freeCompilerArgs += [
"-P",
"plugin:androidx.compose.compiler.plugins.kotlin:suppressKotlinVersionCompatibilityCheck=true"
]
}
buildFeatures {
compose true
}
composeOptions {
kotlinCompilerExtensionVersion compose_version
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.3.2'
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'com.google.android.material:material:1.3.0'
implementation 'androidx.activity:activity-compose:1.3.0-alpha02'
implementation "androidx.compose.ui:ui:$compose_version"
implementation "androidx.compose.ui:ui:$compose_version"
implementation "androidx.compose.material:material:$compose_version"
implementation "androidx.compose.ui:ui-tooling:$compose_version"
implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.0'
testImplementation 'junit:junit:4.+'
androidTestImplementation 'androidx.test.ext:junit:1.1.2'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
}
The culprit is the line classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.30-RC" which should instead be 1.4.30 without the -RC. The reason I had the initial -RC version was because the latest Android Studio Kotlin plugin version is indeed the -RC (frustrating that IntelliJ doesn't release the correct version even though it seems to be available in gradle), and using 1.4.30 gave a warning that it was different from the IDE version. Ignoring that warning and using the release version fixed that problem.
Sigh!
I've been messing around with Jetpack Compose recently and I had gone through the basic tutorial here. Then I started looking at the Jetnewssample project they have. Now I'm ready to start working on my own project but now when I create a new project in the same parent directory as the Jetnewssample project, (which is working fine) Android Studio can no longer import androidx.ui.core.Text or androidx.ui.core.setContent. I can import other classes from the same location but now I just get an unresolved reference error. This is a new project set to start with an Empty Compose Activity. Here is the code:
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.compose.Composable
import androidx.ui.core.Text
import androidx.ui.core.setContent
import androidx.ui.material.MaterialTheme
import androidx.ui.tooling.preview.Preview
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
MaterialTheme {
Greeting("Android")
}
}
}
}
#Composable
fun Greeting(name: String) {
Text(text = "Hello $name!")
}
#Preview
#Composable
fun DefaultPreview() {
MaterialTheme {
Greeting("Android")
}
}
Here's the module's gradle build file:
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
android {
compileSdkVersion 29
buildToolsVersion "29.0.2"
defaultConfig {
applicationId "com.franklin.sanctified"
minSdkVersion 21
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility = 1.8
targetCompatibility = 1.8
}
kotlinOptions {
jvmTarget = '1.8'
}
buildFeatures {
compose true
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.core:core-ktx:1.1.0'
implementation 'androidx.ui:ui-layout:0.1.0-dev03'
implementation 'androidx.ui:ui-material:0.1.0-dev03'
implementation 'androidx.ui:ui-tooling:0.1.0-dev03'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}
Update on :May-2021
Add below dependencies in app level Gradle or kts file for set content{ .. }
implementation("androidx.activity:activity-compose:1.3.0-alpha07")
Those seem to be in ui-framework for dev03. Try adding that dependency to your lineup:
implementation "androidx.ui:ui-framework:0.1.0-dev03"
In my case the problem was that I was missing activities integration for compose. setContent is an extension function on ComponentActivity class, defined in package androidx.activity.compose
Just import:
implementation 'androidx.activity:activity-compose:1.4.0'