Jetpack Compose天气应用突现空白，获取Unit列表为空求助

我开发的天气应用一个月前完全正常运行，昨日再次启动时却出现空白屏幕。已确认依赖的API仍可用且正常工作，应用基于Jetpack Compose开发，日志显示getUnitList: Empty List，以下是相关代码、日志信息，恳请帮忙排查：

Settings ViewModel代码 #

@HiltViewModel
class SettingsViewModel @Inject constructor(
    private val repository: WeatherDbRepository
): ViewModel() {
    private val _unitList = MutableStateFlow<List<Unit>>(emptyList())
    val unitList = _unitList.asStateFlow()


    init {
        getUnitList()
    }

    private fun getUnitList() {
        viewModelScope.launch(Dispatchers.IO) {
            repository.getUnits().distinctUntilChanged()
                .collect{listOfUnits ->
                    if (listOfUnits.isNullOrEmpty()){
                        Log.d("TAG", "getUnitList: Empty List")
                    }else{
                        _unitList.value = listOfUnits
                    }

                }
        }
    }


    fun insertUnit(unit: Unit) = viewModelScope.launch { repository.insertUnit(unit) }
    fun updateUnit(unit: Unit) = viewModelScope.launch { repository.updateUnit(unit) }
    fun deleteUnit(unit: Unit) = viewModelScope.launch { repository.deleteUnit(unit) }
    fun deleteAllUnits() = viewModelScope.launch { repository.deleteAllUnits() }

} 

Repository代码 #

class WeatherDbRepository @Inject constructor(private val weatherDao: WeatherDao) {

    fun getFavorites(): Flow<List<Favorite>> = weatherDao.getFavorites()
    suspend fun insertFavorite(favorite: Favorite) = weatherDao.insertFavorite(favorite)
    suspend fun updateFavorite(favorite: Favorite) = weatherDao.updateFavorite(favorite)
    suspend fun deleteALlFavorite() = weatherDao.deleteAllFavorites()
    suspend fun deleteFavorite(favorite: Favorite) = weatherDao.deleteFavorite(favorite)
    suspend fun getFavById(city: String): Favorite = weatherDao.getFavByID(city)

    fun getUnits(): Flow<List<Unit>> = weatherDao.getUnits()
    suspend fun insertUnit(unit: Unit) = weatherDao.insertUnit(unit)
    suspend fun updateUnit(unit: Unit) = weatherDao.updateUnt(unit)
    suspend fun deleteAllUnits() = weatherDao.deleteAllUnits()
    suspend fun deleteUnit(unit: Unit) = weatherDao.deleteUnit(unit)

}

App Module(依赖注入)代码 #

@Module
@InstallIn(SingletonComponent::class)
class AppModule {

    @Provides
    @Singleton
    fun provideWeatherDao(weatherDatabase: WeatherDatabase): WeatherDao =
        weatherDatabase.weatherDao()

    @Provides
    @Singleton
    fun provideWeatherDatabase(@ApplicationContext context: Context): WeatherDatabase =
        Room.databaseBuilder(
            context,
            WeatherDatabase::class.java,
            "weatherD"
        )
            .fallbackToDestructiveMigration()
            .build()

    @Provides
    @Singleton
    fun provideOpenWeatherApi(): WeatherApi {
        return Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .build()
            .create(WeatherApi::class.java)
    }

}

相关日志 #

08/07 15:03:47: Launching 'app' on Pixel 3 XL API 30.
Install successfully finished in 696 ms.
$ adb shell am start -n "com.example.weatherapp/com.example.weatherapp.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Connected to process 3468 on device 'Pixel_3_XL_API_30 [emulator-5554]'.
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/mple.weatherap: Late-enabling -Xcheck:jni
I/mple.weatherap: Unquickening 12 vdex files!
W/mple.weatherap: Unexpected CPU variant for X86 using defaults: x86
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/libEGL: loaded /vendor/lib/egl/libEGL_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv1_CM_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv2_emulation.so
W/mple.weatherap: Class androidx.compose.runtime.snapshots.SnapshotStateList failed lock verification and will run slower.
    Common causes for lock verification issues are non-optimized dex code
    and incorrect proguard optimizations.
D/HostConnection: HostConnection::get() New Host Connection established 0xf2f8fa50, tid 3495
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2 
W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
D/EGL_emulation: eglCreateContext: 0xf2f90d90: maj 2 min 0 rcv 2
D/EGL_emulation: eglMakeCurrent: 0xf2f90d90: ver 2 0 (tinfo 0xf32f1c90) (first time)
I/Gralloc4: mapper 4.x is not supported
D/HostConnection: createUnique: call
D/HostConnection: HostConnection::get() New Host Connection established 0xf2f92d10, tid 3495
D/goldfish-address-space: allocate: Ask for block of size 0x100
D/goldfish-address-space: allocate: ioctl allocate returned offset 0x3efffe000 size 0x2000
D/HostConnection: HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_vulkan ANDROID_EMU_deferred_vulkan_commands ANDROID_EMU_vulkan_null_optional_strings ANDROID_EMU_vulkan_create_resources_with_requirements ANDROID_EMU_YUV_Cache ANDROID_EMU_vulkan_ignored_handles ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_vulkan_free_memory_sync ANDROID_EMU_vulkan_shader_float16_int8 ANDROID_EMU_vulkan_async_queue_submit ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2 
I/OpenGLRenderer: Davey! duration=727ms; Flags=1, IntendedVsync=1214569752715, Vsync=1214653086045, OldestInputEvent=9223372036854775807, NewestInputEvent=0, HandleInputStart=1214662199300, AnimationStart=1214662216300, PerformTraversalsStart=1214662432500, DrawStart=1215266847200, SyncQueued=1215283423600, SyncStart=1215284670600, IssueDrawCommandsStart=1215284716800, SwapBuffers=1215296537700, FrameCompleted=1215298216000, DequeueBufferDuration=186800, QueueBufferDuration=588900, GpuCompleted=72904454231491230, 
I/Choreographer: Skipped 34 frames!  The application may be doing too much work on its main thread.
W/mple.weatherap: Accessing hidden method Ljava/lang/invoke/MethodHandles$Lookup;-><init>(Ljava/lang/Class;I)V (greylist, reflection, allowed)
D/TAG: getUnitList: Empty List
D/ProfileInstaller: Installing profile for com.example.weatherapp

内容的提问来源于stack exchange，提问作者OEThe11