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【学习路线】Android开发2025：从入门到高级架构师

news 2025/7/29 17:07:50

前言

Android开发作为移动应用开发的核心领域，经历了从Java到Kotlin、从XML布局到Jetpack Compose的巨大变革。2025年的Android开发已经进入了全新的时代，本学习路线将带你从入门到高级架构师，掌握最新的技术栈和最佳实践。

一、Android开发基础阶段

（一）开发环境搭建

1.1 开发工具安装

# Android Studio安装
# 1. 下载地址：https://developer.android.com/studio
# 2. 推荐版本：Android Studio Hedgehog | 2023.1.1
# 3. 系统要求：
#    - Windows 10/11 64位
#    - macOS 10.14 (Mojave) 或更高
#    - Ubuntu 14.04 LTS 或更高# SDK配置
# 1. Android SDK Platform 34
# 2. Android SDK Build-Tools 34.0.0
# 3. Android Emulator
# 4. Android SDK Platform-Tools

1.2 第一个Android应用

// MainActivity.kt
class MainActivity : ComponentActivity() {override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContent {MyApplicationTheme {Surface(modifier = Modifier.fillMaxSize(),color = MaterialTheme.colorScheme.background) {Greeting("Android")}}}}
}@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {Text(text = "Hello $name!",modifier = modifier)
}

（二）Kotlin语言基础

2.1 Kotlin核心语法

// 数据类
data class User(val id: Int,val name: String,val email: String
)// 扩展函数
fun String.isEmailValid(): Boolean {return android.util.Patterns.EMAIL_ADDRESS.matcher(this).matches()
}// 协程基础
suspend fun fetchUserData(): List<User> {return withContext(Dispatchers.IO) {// 模拟网络请求delay(1000)listOf(User(1, "张三", "zhangsan@example.com"),User(2, "李四", "lisi@example.com"))}
}

2.2 Kotlin高阶函数

// 函数式编程
val numbers = listOf(1, 2, 3, 4, 5)
val doubled = numbers.map { it * 2 }
val sum = numbers.reduce { acc, i -> acc + i }// DSL构建器
class AlertDialogBuilder {var title: String = ""var message: String = ""var positiveButton: String = ""var onPositiveClick: () -> Unit = {}fun build(): AlertDialog {return AlertDialog.Builder(context).setTitle(title).setMessage(message).setPositiveButton(positiveButton) { _, _ -> onPositiveClick() }.create()}
}

（三）Android核心组件

3.1 Activity与Fragment

// 现代Activity实现
class MainActivity : ComponentActivity() {private val viewModel: MainViewModel by viewModels()override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContent {MyAppTheme {val navController = rememberNavController()NavHost(navController = navController,startDestination = "home") {composable("home") { HomeScreen(navController) }composable("detail/{id}") { backStackEntry ->val id = backStackEntry.arguments?.getString("id")DetailScreen(id, navController)}}}}}
}// Fragment与ViewModel
class UserFragment : Fragment() {private val viewModel: UserViewModel by viewModels()override fun onCreateView(inflater: LayoutInflater,container: ViewGroup?,savedInstanceState: Bundle?): View {return ComposeView(requireContext()).apply {setContent {UserScreen(viewModel)}}}
}

3.2 数据存储

// Room数据库
@Entity(tableName = "users")
data class UserEntity(@PrimaryKey val id: Int,val name: String,val email: String,val createdAt: Long = System.currentTimeMillis()
)@Dao
interface UserDao {@Query("SELECT * FROM users WHERE id = :id")suspend fun getUserById(id: Int): UserEntity?@Insert(onConflict = OnConflictStrategy.REPLACE)suspend fun insertUser(user: UserEntity)@Query("SELECT * FROM users ORDER BY createdAt DESC")fun getAllUsers(): Flow<List<UserEntity>>
}@Database(entities = [UserEntity::class], version = 1)
abstract class AppDatabase : RoomDatabase() {abstract fun userDao(): UserDao
}// DataStore偏好存储
class UserPreferences(private val dataStore: DataStore<Preferences>) {private val USER_NAME = stringPreferencesKey("user_name")private val IS_FIRST_LAUNCH = booleanPreferencesKey("is_first_launch")val userName: Flow<String> = dataStore.data.map { preferences -> preferences[USER_NAME] ?: "" }suspend fun saveUserName(name: String) {dataStore.edit { preferences ->preferences[USER_NAME] = name}}
}

二、UI开发进阶

（一）Jetpack Compose全面掌握

1.1 Compose基础组件

// 状态管理
@Composable
fun CounterScreen() {var count by remember { mutableStateOf(0) }Column(modifier = Modifier.fillMaxSize().padding(16.dp),horizontalAlignment = Alignment.CenterHorizontally,verticalArrangement = Arrangement.Center) {Text(text = "Count: $count",style = MaterialTheme.typography.headlineMedium)Spacer(modifier = Modifier.height(16.dp))Button(onClick = { count++ }) {Text("Increment")}}
}// 列表和网格
@Composable
fun UserList(users: List<User>) {LazyColumn(modifier = Modifier.fillMaxSize(),contentPadding = PaddingValues(16.dp),verticalArrangement = Arrangement.spacedBy(8.dp)) {items(users) { user ->UserCard(user = user)}}
}@Composable
fun UserCard(user: User) {Card(modifier = Modifier.fillMaxWidth(),elevation = CardDefaults.cardElevation(defaultElevation = 4.dp)) {Row(modifier = Modifier.fillMaxWidth().padding(16.dp),verticalAlignment = Alignment.CenterVertically) {AsyncImage(model = user.avatarUrl,contentDescription = "User avatar",modifier = Modifier.size(48.dp).clip(CircleShape))Spacer(modifier = Modifier.width(16.dp))Column {Text(text = user.name,style = MaterialTheme.typography.titleMedium)Text(text = user.email,style = MaterialTheme.typography.bodyMedium,color = MaterialTheme.colorScheme.onSurfaceVariant)}}}
}

1.2 Compose动画与过渡

// 动画效果
@Composable
fun AnimatedVisibilityExample() {var visible by remember { mutableStateOf(true) }Column {Button(onClick = { visible = !visible }) {Text("Toggle Visibility")}AnimatedVisibility(visible = visible,enter = fadeIn() + slideInVertically(),exit = fadeOut() + slideOutVertically()) {Card(modifier = Modifier.fillMaxWidth().padding(16.dp)) {Text("Animated Content",modifier = Modifier.padding(16.dp))}}}
}// 自定义动画
@Composable
fun LoadingAnimation() {val infiniteTransition = rememberInfiniteTransition()val rotation by infiniteTransition.animateFloat(initialValue = 0f,targetValue = 360f,animationSpec = infiniteRepeatable(animation = tween(1000, easing = LinearEasing),repeatMode = RepeatMode.Restart))Box(modifier = Modifier.fillMaxSize(),contentAlignment = Alignment.Center) {CircularProgressIndicator(modifier = Modifier.rotate(rotation))}
}

（二）Material Design 3

2.1 主题和样式

// Material 3主题配置
private val DarkColorScheme = darkColorScheme(primary = Purple80,secondary = PurpleGrey80,tertiary = Pink80
)private val LightColorScheme = lightColorScheme(primary = Purple40,secondary = PurpleGrey40,tertiary = Pink40
)@Composable
fun MyAppTheme(darkTheme: Boolean = isSystemInDarkTheme(),content: @Composable () -> Unit
) {val colorScheme = when {darkTheme -> DarkColorSchemeelse -> LightColorScheme}MaterialTheme(colorScheme = colorScheme,typography = Typography,content = content)
}// 动态颜色
@Composable
fun DynamicTheme(darkTheme: Boolean = isSystemInDarkTheme(),content: @Composable () -> Unit
) {val context = LocalContext.currentval colorScheme = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {if (darkTheme) dynamicDarkColorScheme(context)else dynamicLightColorScheme(context)} else {if (darkTheme) DarkColorScheme else LightColorScheme}MaterialTheme(colorScheme = colorScheme,typography = Typography,content = content)
}

三、架构设计模式

（一）MVVM架构

1.1 ViewModel实现

// ViewModel基类
abstract class BaseViewModel : ViewModel() {protected val _uiState = MutableStateFlow(UiState())val uiState: StateFlow<UiState> = _uiState.asStateFlow()protected val _event = MutableSharedFlow<Event>()val event: SharedFlow<Event> = _event.asSharedFlow()protected fun launch(onError: (Throwable) -> Unit = {},onSuccess: suspend () -> Unit) {viewModelScope.launch {try {onSuccess()} catch (e: Exception) {onError(e)_event.emit(Event.Error(e.message ?: "Unknown error"))}}}
}// 具体ViewModel
class UserViewModel(private val userRepository: UserRepository,private val savedStateHandle: SavedStateHandle
) : BaseViewModel() {private val userId: String = savedStateHandle["userId"] ?: ""init {loadUser()}private fun loadUser() {launch(onError = { error ->_uiState.update { it.copy(isLoading = false, error = error.message) }}) {_uiState.update { it.copy(isLoading = true) }val user = userRepository.getUser(userId)_uiState.update { it.copy(isLoading = false, user = user) }}}fun updateUser(user: User) {launch {userRepository.updateUser(user)_event.emit(Event.UserUpdated)}}
}// UI状态
data class UiState(val isLoading: Boolean = false,val user: User? = null,val error: String? = null
)sealed class Event {data class Error(val message: String) : Event()object UserUpdated : Event()
}

（二）Clean Architecture

2.1 分层架构

app/
├── presentation/
│   ├── ui/
│   │   ├── screens/
│   │   ├── components/
│   │   └── theme/
│   └── viewmodel/
├── domain/
│   ├── model/
│   ├── repository/
│   └── usecase/
└── data/├── local/├── remote/└── repository/

2.2 领域层

// 实体
data class User(val id: String,val name: String,val email: String,val avatarUrl: String?
)// 仓库接口
interface UserRepository {suspend fun getUser(id: String): Result<User>suspend fun getUsers(): Result<List<User>>suspend fun updateUser(user: User): Result<Unit>suspend fun deleteUser(id: String): Result<Unit>
}// 用例
class GetUserUseCase(private val userRepository: UserRepository
) {suspend operator fun invoke(id: String): Result<User> {return userRepository.getUser(id)}
}class GetUsersUseCase(private val userRepository: UserRepository
) {suspend operator fun invoke(): Result<List<User>> {return userRepository.getUsers()}
}

2.3 数据层

// 远程数据源
class UserRemoteDataSource(private val apiService: UserApiService
) {suspend fun getUser(id: String): UserDto {return apiService.getUser(id)}suspend fun getUsers(): List<UserDto> {return apiService.getUsers()}
}// 本地数据源
class UserLocalDataSource(private val userDao: UserDao
) {suspend fun getUser(id: String): UserEntity? {return userDao.getUserById(id)}suspend fun saveUsers(users: List<UserEntity>) {userDao.insertUsers(users)}
}// 仓库实现
class UserRepositoryImpl(private val remoteDataSource: UserRemoteDataSource,private val localDataSource: UserLocalDataSource,private val networkManager: NetworkManager
) : UserRepository {override suspend fun getUser(id: String): Result<User> {return try {if (networkManager.isConnected()) {val userDto = remoteDataSource.getUser(id)val user = userDto.toDomain()localDataSource.saveUser(user.toEntity())Result.success(user)} else {val userEntity = localDataSource.getUser(id)userEntity?.toDomain()?.let { Result.success(it) }?: Result.failure(Exception("User not found"))}} catch (e: Exception) {Result.failure(e)}}
}

四、网络与数据层

（一）网络通信

1.1 Retrofit + OkHttp

// API接口
interface UserApiService {@GET("users/{id}")suspend fun getUser(@Path("id") id: String): UserDto@GET("users")suspend fun getUsers(@Query("page") page: Int,@Query("limit") limit: Int): List<UserDto>@POST("users")suspend fun createUser(@Body user: CreateUserRequest): UserDto@PUT("users/{id}")suspend fun updateUser(@Path("id") id: String,@Body user: UpdateUserRequest): UserDto@DELETE("users/{id}")suspend fun deleteUser(@Path("id") id: String)
}// 网络配置
object NetworkModule {private const val BASE_URL = "https://api.example.com/"private val okHttpClient = OkHttpClient.Builder().connectTimeout(30, TimeUnit.SECONDS).readTimeout(30, TimeUnit.SECONDS).writeTimeout(30, TimeUnit.SECONDS).addInterceptor(AuthInterceptor()).addInterceptor(LoggingInterceptor()).build()private val retrofit = Retrofit.Builder().baseUrl(BASE_URL).client(okHttpClient).addConverterFactory(GsonConverterFactory.create()).build()val userApiService: UserApiService = retrofit.create(UserApiService::class.java)
}// 认证拦截器
class AuthInterceptor : Interceptor {override fun intercept(chain: Interceptor.Chain): Response {val originalRequest = chain.request()val authenticatedRequest = originalRequest.newBuilder().header("Authorization", "Bearer ${TokenManager.getToken()}").build()return chain.proceed(authenticatedRequest)}
}

（二）数据持久化

2.1 Room数据库高级用法

// 复杂查询
@Dao
interface UserDao {@Query("""SELECT * FROM users WHERE name LIKE '%' || :query || '%' OR email LIKE '%' || :query || '%'ORDER BY createdAt DESC""")fun searchUsers(query: String): Flow<List<UserEntity>>@Query("""SELECT * FROM users WHERE createdAt BETWEEN :startDate AND :endDateORDER BY createdAt DESCLIMIT :limit OFFSET :offset""")suspend fun getUsersByDateRange(startDate: Long,endDate: Long,limit: Int,offset: Int): List<UserEntity>@Transactionsuspend fun insertUserWithPosts(user: UserEntity, posts: List<PostEntity>) {insertUser(user)insertPosts(posts)}
}// 数据库迁移
@Database(entities = [UserEntity::class, PostEntity::class],version = 2,exportSchema = true,autoMigrations = [AutoMigration(from = 1, to = 2)]
)
abstract class AppDatabase : RoomDatabase() {abstract fun userDao(): UserDaoabstract fun postDao(): PostDaocompanion object {val MIGRATION_1_2 = object : Migration(1, 2) {override fun migrate(database: SupportSQLiteDatabase) {database.execSQL("""ALTER TABLE users ADD COLUMN lastLoginAt INTEGER DEFAULT 0""")}}}
}

五、性能优化

（一）内存优化

1.1 内存泄漏检测

// LeakCanary集成
class MyApplication : Application() {override fun onCreate() {super.onCreate()if (LeakCanary.isInAnalyzerProcess(this)) {return}LeakCanary.install(this)}
}// 内存优化工具
object MemoryProfiler {fun logMemoryUsage(tag: String) {val runtime = Runtime.getRuntime()val usedMemory = runtime.totalMemory() - runtime.freeMemory()val maxMemory = runtime.maxMemory()val availableMemory = maxMemory - usedMemoryLog.d(tag, "Used: ${usedMemory / 1024 / 1024}MB")Log.d(tag, "Available: ${availableMemory / 1024 / 1024}MB")}
}

1.2 图片加载优化

// Coil图片加载
class ImageLoaderModule {companion object {fun provideImageLoader(context: Context): ImageLoader {return ImageLoader.Builder(context).memoryCache {MemoryCache.Builder(context).maxSizePercent(0.25).build()}.diskCache {DiskCache.Builder().directory(context.cacheDir.resolve("image_cache")).maxSizeBytes(50 * 1024 * 1024) // 50MB.build()}.crossfade(true).build()}}
}// 图片压缩
object ImageCompressor {fun compressImage(context: Context,uri: Uri,maxWidth: Int = 1080,maxHeight: Int = 1920,quality: Int = 80): File {val bitmap = BitmapFactory.decodeStream(context.contentResolver.openInputStream(uri))val scaledBitmap = Bitmap.createScaledBitmap(bitmap,maxWidth,maxHeight,true)val outputFile = File(context.cacheDir, "compressed_${System.currentTimeMillis()}.jpg")FileOutputStream(outputFile).use { out ->scaledBitmap.compress(Bitmap.CompressFormat.JPEG, quality, out)}return outputFile}
}

（二）网络优化

2.1 网络缓存策略

// OkHttp缓存配置
object CacheConfig {private const val CACHE_SIZE = 10 * 1024 * 1024L // 10MBfun provideCache(context: Context): Cache {return Cache(context.cacheDir, CACHE_SIZE)}fun provideCacheInterceptor(): Interceptor {return Interceptor { chain ->val response = chain.proceed(chain.request())val cacheControl = CacheControl.Builder().maxAge(1, TimeUnit.HOURS).build()response.newBuilder().header("Cache-Control", cacheControl.toString()).build()}}
}

六、测试与调试

（一）单元测试

1.1 ViewModel测试

@RunWith(MockitoJUnitRunner::class)
class UserViewModelTest {@Mockprivate lateinit var userRepository: UserRepositoryprivate lateinit var viewModel: UserViewModel@Beforefun setup() {viewModel = UserViewModel(userRepository)}@Testfun `getUser should update UI state with user data`() = runTest {// Givenval userId = "123"val user = User(userId, "Test User", "test@example.com")whenever(userRepository.getUser(userId)).thenReturn(Result.success(user))// WhenviewModel.loadUser(userId)// ThenviewModel.uiState.test {val state = awaitItem()assertEquals(false, state.isLoading)assertEquals(user, state.user)}}
}

（二）UI测试

2.1 Compose UI测试

class UserScreenTest {@get:Ruleval composeTestRule = createComposeRule()@Testfun userList_displaysCorrectly() {val users = listOf(User("1", "Alice", "alice@example.com"),User("2", "Bob", "bob@example.com"))composeTestRule.setContent {UserList(users = users)}composeTestRule.onNodeWithText("Alice").assertIsDisplayed()composeTestRule.onNodeWithText("Bob").assertIsDisplayed()}@Testfun userCard_clickAction() {var clickedUser: User? = nullval user = User("1", "Alice", "alice@example.com")composeTestRule.setContent {UserCard(user = user,onUserClick = { clickedUser = it })}composeTestRule.onNodeWithText("Alice").performClick()assertEquals(user, clickedUser)}
}

七、高级架构与组件化

（一）模块化架构

1.1 模块划分

app/
├── app/
│   ├── src/main/java/com/example/app/
│   │   ├── MainActivity.kt
│   │   └── MyApplication.kt
├── core/
│   ├── data/
│   ├── domain/
│   └── ui/
├── features/
│   ├── home/
│   ├── profile/
│   └── settings/
└── libraries/├── network/├── database/└── common/

1.2 动态功能模块

// build.gradle (Dynamic Feature)
plugins {id 'com.android.dynamic-feature'id 'kotlin-android'
}android {compileSdk 34defaultConfig {minSdk 21testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"}
}dependencies {implementation project(':app')implementation "androidx.compose.ui:ui:$compose_version"implementation "androidx.compose.material3:material3:$compose_version"
}

（二）依赖注入

2.1 Hilt集成

// Application类
@HiltAndroidApp
class MyApplication : Application()// 模块配置
@Module
@InstallIn(SingletonComponent::class)
object AppModule {@Provides@Singletonfun provideDatabase(@ApplicationContext context: Context): AppDatabase {return Room.databaseBuilder(context,AppDatabase::class.java,"app_database").build()}@Provides@Singletonfun provideUserRepository(userDao: UserDao,userApiService: UserApiService): UserRepository {return UserRepositoryImpl(userDao, userApiService)}
}// ViewModel注入
@HiltViewModel
class UserViewModel @Inject constructor(private val getUserUseCase: GetUserUseCase,private val savedStateHandle: SavedStateHandle
) : ViewModel() {// ViewModel实现
}

八、现代Android开发

（一）Jetpack Compose高级特性

1.1 动画系统

// 复杂动画
@Composable
fun AnimatedCard(isExpanded: Boolean,onToggle: () -> Unit
) {val transition = updateTransition(targetState = isExpanded,label = "card_transition")val cardElevation by transition.animateDp(label = "elevation") { expanded ->if (expanded) 8.dp else 2.dp}val cardCornerRadius by transition.animateDp(label = "corner_radius") { expanded ->if (expanded) 16.dp else 8.dp}Card(elevation = CardDefaults.cardElevation(defaultElevation = cardElevation),shape = RoundedCornerShape(cardCornerRadius),modifier = Modifier.fillMaxWidth().clickable { onToggle() }) {// Card content}
}// 共享元素动画
@Composable
fun SharedElementTransition(isVisible: Boolean,sharedTransitionScope: SharedTransitionScope,animatedVisibilityScope: AnimatedVisibilityScope
) {with(sharedTransitionScope) {Card(modifier = Modifier.sharedBounds(rememberSharedContentState(key = "card"),animatedVisibilityScope)) {// Content}}
}

（二）现代架构组件

2.1 Navigation Compose

// 导航配置
@Composable
fun AppNavigation() {val navController = rememberNavController()NavHost(navController = navController,startDestination = "home") {composable("home") {HomeScreen(onUserClick = { userId ->navController.navigate("user/$userId")})}composable("user/{userId}",arguments = listOf(navArgument("userId") { type = NavType.StringType })) { backStackEntry ->val userId = backStackEntry.arguments?.getString("userId")UserDetailScreen(userId = userId,onBackClick = { navController.popBackStack() })}// 深度链接composable("user/{userId}",deepLinks = listOf(navDeepLink { uriPattern = "https://example.com/user/{userId}" })) { backStackEntry ->// Handle deep link}}
}

九、性能监控与优化

（一）性能分析工具

1.1 Android Profiler使用

// 性能监控
class PerformanceMonitor {companion object {fun startMethodTracing(traceName: String) {Debug.startMethodTracing(traceName)}fun stopMethodTracing() {Debug.stopMethodTracing()}fun measureTime(block: () -> Unit): Long {val startTime = System.currentTimeMillis()block()return System.currentTimeMillis() - startTime}}
}

（二）崩溃分析

2.1 Firebase Crashlytics

// 崩溃报告
class CrashReportingTree : Timber.Tree() {override fun log(priority: Int, tag: String?, message: String, t: Throwable?) {if (priority == Log.ERROR || priority == Log.WARN) {FirebaseCrashlytics.getInstance().log(message)t?.let { FirebaseCrashlytics.getInstance().recordException(it) }}}
}// 自定义异常处理
class CustomExceptionHandler : Thread.UncaughtExceptionHandler {private val defaultHandler = Thread.getDefaultUncaughtExceptionHandler()override fun uncaughtException(thread: Thread, throwable: Throwable) {// 记录崩溃信息saveCrashInfo(throwable)// 上传到服务器uploadCrashReport(throwable)// 调用默认处理defaultHandler?.uncaughtException(thread, throwable)}
}

十、发布与持续集成

（一）CI/CD配置

1.1 GitHub Actions

# .github/workflows/android.yml
name: Android CIon:push:branches: [ main, develop ]pull_request:branches: [ main ]jobs:test:runs-on: ubuntu-lateststeps:- uses: actions/checkout@v3- name: Set up JDK 17uses: actions/setup-java@v3with:java-version: '17'distribution: 'temurin'- name: Cache Gradle packagesuses: actions/cache@v3with:path: |~/.gradle/caches~/.gradle/wrapperkey: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}- name: Run testsrun: ./gradlew test- name: Build APKrun: ./gradlew assembleDebug- name: Upload APKuses: actions/upload-artifact@v3with:name: app-debugpath: app/build/outputs/apk/debug/app-debug.apk

（二）应用签名与发布

2.1 签名配置

// app/build.gradle
android {signingConfigs {release {storeFile file("keystore/release.keystore")storePassword System.getenv("KEYSTORE_PASSWORD")keyAlias System.getenv("KEY_ALIAS")keyPassword System.getenv("KEY_PASSWORD")}}buildTypes {release {signingConfig signingConfigs.releaseminifyEnabled trueproguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'}}
}

十一、学习资源与路线图

（一）官方资源

Android开发者官网: https://developer.android.com/
Kotlin官方文档: https://kotlinlang.org/docs/
Jetpack Compose: https://developer.android.com/jetpack/compose

（二）推荐书籍

《Android编程权威指南》
《Kotlin实战》
《Clean Architecture》
《Android高级编程》

（三）在线课程

Google Codelabs: https://codelabs.developers.google.com/
Udacity Android课程: https://www.udacity.com/course/android-kotlin-developer-nanodegree–nd940
Coursera Android专项课程: https://www.coursera.org/specializations/android-app-development