kotlin
package com.example.myapp.billing

import android.app.Activity
import android.content.Context
import com.android.billingclient.api.*
import kotlinx.coroutines.flow.MutableStateFlow

In-app billing with Google Play

kotlin android billing
by Alex Chen 1 tab
kotlin
package com.example.myapp.services

import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.PendingIntent
import android.app.Service

Service and foreground notifications

kotlin android service
by Alex Chen 1 tab
kotlin
package com.example.myapp.utils

import android.app.NotificationChannel
import android.app.NotificationChannelGroup
import android.app.NotificationManager
import android.app.PendingIntent

Notification channels and categories

kotlin android notifications
by Alex Chen 1 tab
kotlin
package com.example.myapp.widget

import android.app.PendingIntent
import android.appwidget.AppWidgetManager
import android.appwidget.AppWidgetProvider
import android.content.Context

App widgets for home screen

kotlin android widget
by Alex Chen 2 tabs
kotlin
package com.example.myapp.receivers

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter

Broadcast Receivers for system events

kotlin android broadcastreceiver
by Alex Chen 2 tabs
kotlin
package com.example.myapp.ui

import androidx.lifecycle.*
import kotlinx.coroutines.launch

class UserViewModel(

LiveData transformations and mediators

kotlin android livedata
by Alex Chen 1 tab
kotlin
package com.example.myapp.ui.custom

import android.content.Context
import android.util.AttributeSet
import android.view.ViewGroup
import kotlin.math.max

Custom ViewGroup for advanced layouts

kotlin android custom-view
by Alex Chen 2 tabs
kotlin
package com.example.myapp.utils

import android.app.DownloadManager
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent

Download Manager for file downloads

kotlin android downloadmanager
by Alex Chen 1 tab
kotlin
package com.example.myapp.utils

import android.content.Context
import androidx.biometric.BiometricManager
import androidx.biometric.BiometricPrompt
import androidx.core.content.ContextCompat

Biometric authentication implementation

kotlin android biometric
by Alex Chen 2 tabs
kotlin
package com.example.myapp.ui.camera

import android.Manifest
import android.content.pm.PackageManager
import android.os.Bundle
import android.util.Log

CameraX for camera functionality

kotlin android camerax
by Alex Chen 1 tab
kotlin
package com.example.myapp.ui.player

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.example.myapp.databinding.ActivityVideoPlayerBinding
import com.google.android.exoplayer2.ExoPlayer

ExoPlayer for media playback

kotlin android exoplayer
by Alex Chen 2 tabs
kotlin
package com.example.myapp.data

import android.content.Context
import androidx.datastore.core.DataStore
import androidx.datastore.preferences.core.*
import androidx.datastore.preferences.preferencesDataStore

DataStore for modern preferences

kotlin android datastore
by Alex Chen 2 tabs