【ANDROID STUDIO】The Application Class With Dagger

 package com.example.dagger

import android.app.Application
class SmartPhoneApplication : Application() {
    lateinit var smartPhoneComponent: SmartPhoneComponent
    override
    fun onCreate() {
        smartPhoneComponent = initDagger()
        super.onCreate()
    }

    private fun initDagger(): SmartPhoneComponent =
        DaggerSmartPhoneComponent.builder()
            .memoryCardModule(MemoryCardModule(1000))
            .build()
}

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

    <application
        android:name=".SmartPhoneApplication"
        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/AppTheme">
        <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>

package com.example.dagger

import dagger.Component

@Component(modules = [MemoryCardModule::class, NCBatteryModule::class])
interface SmartPhoneComponent {
     fun inject(mainActivity: MainActivity)
}