CODEWITHSUNDEEP
androidandroid-studiokotlindependency-injectiondagger-hilt
Ahmed Muhammed
Ahmed Muhammed

Reputation: 285

lateinit property str has not been initialized

I'm currently learning Dagger Hilt but I've come across an issue:


kotlin.UninitializedPropertyAccessException: lateinit property str has not been initialized
        at com.example.kotlin20test.MainActivity.getStr(MainActivity.kt:24)
        at com.example.kotlin20test.MainActivity.onCreate(MainActivity.kt:34)
        at android.app.Activity.performCreate(Activity.java:7802)
        at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)

Here are my files:

MainActivity:


@AndroidEntryPoint
class MainActivity : AppCompatActivity() {


    @Inject lateinit var str: String
    @Inject private lateinit var api: JsonPlaceholderApi

    lateinit var mainBinding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        
        mainBinding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(R.layout.activity_main)

        
       if(str != null){
           println(str)
       }


    }}

MyModule:


@Module
@InstallIn(SingletonComponent::class)
object MyModule{

 @Provides
    fun provideString(): String{
        return "Look, It's a string"
    }


}

And I've also tried Retrofit with hilt and it gave me the same error, and I've read many Stack overflow regarding this issue and tried the answers but nothing seems to work.

Edit: I forgot to add the app class and the manifest so here it is:

MyApp


@HiltAndroidApp
class MyApp : Application(){
}

AndroidManifest


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.kotlin20test">

    <application
        android:name=".MyApp"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Kotlin20Test">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Thanks in advance.

Upvotes: 1

Views: 1330

Answers (3)

Zaid Zakir
Zaid Zakir

Reputation: 563

hey you forget the @Singleton annotation

@Module
@InstallIn(SingletonComponent::class)
object MyModule{

@Singleton <------ include this
@Provides
fun provideString(): String{
    return "Look, It's a string"
 }
 }

Upvotes: -1

CliffracerMerchant
CliffracerMerchant

Reputation: 21

The proper way to check if a Kotlin lateinit var has been initialized is with the KProperty value isInitialized, turning this:

if(str != null){
    println(str)
}

into this:

if(::str.isInitialized){
    println(str)
}

Edit: As another user pointed out I erroneously included a ! originally.

Upvotes: 2

tasjapr
tasjapr

Reputation: 1220

While you have not yet initialized your variable, it will give UninitializedPropertyAccessException when you try to get it, even for str != null

as @VelocityCubeR said, kotlin have other method to check if a property has been initialized, buе he was wrong with !

you must change str != null to ::str.isInitialized

Dagger Hilt not relevant to this exception, this is basic kotlin syntax, read more here

Upvotes: 0

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