不确定自从我尽可能地遵循Hilt View Model Documentation以来我犯了什么错误。
我正在尝试使用 Hilt 在 Android 中实现最基本的依赖注入,但不知何故它不起作用。每当我运行我的应用程序时,它都会在启动时崩溃,抱怨它找不到我的 ViewModel 的零参数构造函数,即使我试图通过 ViewModel 的构造函数注入我的依赖项,并给出这个堆栈跟踪
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myHealthConnect.myweightaverage/com.myHealthConnect.myweightaverage.activity.MainActivity}: java.lang.RuntimeException: Cannot create an instance of class com.myHealthConnect.myweightaverage.viewmodel.MainActivityViewModel
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4169)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4325)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2574)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8757)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)
Caused by: java.lang.RuntimeException: Cannot create an instance of class com.myHealthConnect.myweightaverage.viewmodel.MainActivityViewModel
at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:204)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:324)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:306)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:280)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:53)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:35)
at com.myHealthConnect.myweightaverage.activity.MainActivity.getViewModel(MainActivity.kt:21)
at com.myHealthConnect.myweightaverage.activity.MainActivity.onCreate(MainActivity.kt:29)
at android.app.Activity.performCreate(Activity.java:8591)
at android.app.Activity.performCreate(Activity.java:8570)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1384)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4150)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4325)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2574)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8757)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)
Caused by: java.lang.NoSuchMethodException: com.myHealthConnect.myweightaverage.viewmodel.MainActivityViewModel.<init> []
at java.lang.Class.getConstructor0(Class.java:2363)
at java.lang.Class.getDeclaredConstructor(Class.java:2201)
at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:202)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:324)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:306)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:280)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:53)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:35)
at com.myHealthConnect.myweightaverage.activity.MainActivity.getViewModel(MainActivity.kt:21)
at com.myHealthConnect.myweightaverage.activity.MainActivity.onCreate(MainActivity.kt:29)
at android.app.Activity.performCreate(Activity.java:8591)
at android.app.Activity.performCreate(Activity.java:8570)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1384)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4150)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4325)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2574)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8757)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)
以下是相关文件:
项目级build.gradle
// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
id 'com.android.application' version '7.3.0' apply false
id 'com.android.library' version '7.3.0' apply false
id 'org.jetbrains.kotlin.android' version '1.8.0' apply false\
}
应用程序级build.gradle:
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'kotlin-kapt'
id("com.google.dagger.hilt.android") version "2.45" apply false
}
android {
namespace 'com.myHealthConnect.myweightaverage'
compileSdk 33
defaultConfig {
applicationId "com.myHealthConnect.myweightaverage"
minSdk 26
targetSdk 33
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'
}
dataBinding {
enabled = true
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.10.0'
implementation 'androidx.appcompat:appcompat:1.6.1'
implementation 'com.google.android.material:material:1.8.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation 'androidx.health.connect:connect-client:1.0.0-alpha11'
implementation "androidx.activity:activity-ktx:1.7.0"
testImplementation 'junit:junit:4.13.2'
implementation("com.google.dagger:hilt-android:2.45")
kapt("com.google.dagger:hilt-android-compiler:2.45")
androidTestImplementation 'androidx.test.ext:junit:1.1.5'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}
// Allow references to generated code
kapt {
correctErrorTypes = true
javacOptions {
option("-Adagger.hilt.android.internal.disableAndroidSuperclassValidation=true")
}
}
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<!-- Check whether Health Connect is installed or not -->
<queries>
<package android:name="com.google.android.apps.healthdata" />
</queries>
<uses-permission android:name="android.permission.health.READ_WEIGHT"/>
<application
android:name=".application.MyApplication"
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.MyWeightAverage"
android:appComponentFactory="androidx.core.app.CoreComponentFactory"
tools:replace="android:appComponentFactory"
tools:targetApi="31">
<activity
android:name=".activity.MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
<action android:name="androidx.health.ACTION_SHOW_PERMISSIONS_RATIONALE" />
</intent-filter>
<meta-data
android:name="android.app.lib_name"
android:value=""/>
</activity>
</application>
</manifest>
我的应用程序.kt:
import android.app.Application
import dagger.hilt.android.HiltAndroidApp
@HiltAndroidApp
class MyApplication : Application()
AppModule.kt :
import android.content.Context
import androidx.health.connect.client.HealthConnectClient
import dagger.Module
import dagger.Provides
import dagger.hilt.InstallIn
import dagger.hilt.android.components.ViewModelComponent
import dagger.hilt.android.qualifiers.ApplicationContext
import dagger.hilt.android.scopes.ViewModelScoped
import dagger.hilt.components.SingletonComponent
import javax.inject.Singleton
@Module
@InstallIn(ViewModelComponent::class)
object AppModule {
@Provides
@ViewModelScoped
fun provideHealthConnectClient(@ApplicationContext appContext: Context) =
if (HealthConnectClient.isProviderAvailable(appContext)) {
HealthConnectClient.getOrCreate(appContext)
} else {
throw NullPointerException()
}
}
MainActivity.kt:
import android.os.Bundle
import androidx.activity.viewModels
import androidx.appcompat.app.AppCompatActivity
import androidx.databinding.DataBindingUtil
import com.myHealthConnect.myweightaverage.R
import com.myHealthConnect.myweightaverage.databinding.ActivityMainBinding
import com.myHealthConnect.myweightaverage.viewmodel.MainActivityViewModel
import dagger.hilt.android.AndroidEntryPoint
@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
private val viewModel: MainActivityViewModel by viewModels()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val binding: ActivityMainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main)
binding.viewModel = viewModel
binding.lifecycleOwner = this
}
}
MainActivityViewModel.kt :
import androidx.health.connect.client.HealthConnectClient
import androidx.lifecycle.ViewModel
import dagger.hilt.android.lifecycle.HiltViewModel
import javax.inject.Inject
@HiltViewModel
class MainActivityViewModel @Inject constructor(
val healthConnectClient: HealthConnectClient
) : ViewModel() {
init {
}
}