當我更新我的應用程式的某些部分時，我認為我犯了一些錯誤或缺少導致此問題的某些內容，當我嘗試將任何專案保存到收藏夾表時發生問題，保存后我打開相同的專案（再次片段詳細資訊）我應該看到最喜歡的圖示（心形圖示）充滿紅色，這意味著該專案已經保存，如果我再次點擊它應該被洗掉等等......
現在我看到該專案已保存，但是當我單擊后退按鈕并再次單擊該專案時，圖示不會改變，這意味著用戶可以再次保存它（這會導致 recyclerView 中的專案重復）
GIF 中的問題
這是我的代碼
收藏夾物體類
@Parcelize
@Entity(tableName = "favorites")
data class FavoritesEntity(@PrimaryKey(autoGenerate = true) val id: Int, val item: Item) : Parcelable
資料庫類
@Database(
entities = [Item::class, FavoritesEntity::class],
version = 1,
exportSchema = false
) //@TypeConverters(Converters.class)
//@TypeConverters(Converters.class)
//@TypeConverters(Converters.class)
@TypeConverters(ItemTypeConverter::class)
abstract class ItemsDatabase : RoomDatabase() {
// private static ItemsDatabase INSTANCE;
abstract val itemDAO: ItemDAO
companion object {
@Volatile
private var INSTANCE: ItemsDatabase? = null
@Synchronized
fun getInstance(context: Context): ItemsDatabase {
if (INSTANCE == null) {
INSTANCE = Room.databaseBuilder(
context.applicationContext,
ItemsDatabase::class.java,
"items_database"
).fallbackToDestructiveMigration()
.build()
return INSTANCE!!
}
return INSTANCE as ItemsDatabase
}
}
}
專案DAO
@Dao
interface ItemDAO {
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertItem(item: Item)
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertFavorites(favoritesEntity: FavoritesEntity)
@get:Query("SELECT * FROM FAVORITES")
val getAllFavorites: Flow<List<FavoritesEntity>>
@Delete
suspend fun deleteFavorite(favoritesEntity: FavoritesEntity)
@Query("DELETE FROM FAVORITES")
suspend fun deleteAllFavorites()
@Query("SELECT * FROM item_table order by datetime(published) DESC")
fun getAlItems(): Flow<List<Item>>
@Query("SELECT * FROM item_table WHERE title like '%' || :keyword || '%' ")
suspend fun getItemsBySearch(keyword: String?): List<Item>
}
詳細資訊視圖模型
@HiltViewModel
class DetailsViewModel @Inject constructor(
private val mainRepository: MainRepository,
private val dataStoreRepository: DataStoreRepository
) : ViewModel() {
private val _favoritesPostList = MutableLiveData<List<FavoritesEntity>>()
val favoritesPostList: LiveData<List<FavoritesEntity>> get() = _favoritesPostList
fun getFavoritePosts() {
viewModelScope.launch {
mainRepository.localDataSource.getAllFavorites().collect {
_favoritesPostList.value = it
}
}
}
val readRecyclerViewPortraitLayout =
dataStoreRepository.readRecyclerViewPortraitLayout.asLiveData()
val readRecyclerViewLandscapeLayout =
dataStoreRepository.readRecyclerViewLandscpaeLayout.asLiveData()
fun saveRecyclerViewPortraitLayout(layout: String) {
viewModelScope.launch {
dataStoreRepository.saveRecyclerViewPortraitLayout(layout)
}
}
fun saveRecyclerViewLandscapeLayout(layout: String) {
viewModelScope.launch {
dataStoreRepository.saveRecyclerViewLandscapeLayout(layout)
}
}
fun insertFavorites(favoritesEntity: FavoritesEntity) {
viewModelScope.launch(Dispatchers.Default) {
mainRepository.localDataSource.insertFavorites(favoritesEntity)
}
}
fun deleteFavoritePost(favoritesEntity: FavoritesEntity) {
viewModelScope.launch(Dispatchers.IO) {
mainRepository.localDataSource.deleteFavorite(favoritesEntity)
}
}
fun deleteAllFavorites() {
viewModelScope.launch(Dispatchers.IO) {
mainRepository.localDataSource.deleteAllFavorites()
}
}
}
詳情活動
@AndroidEntryPoint
class DetailsActivity : AppCompatActivity() {
private var _binding: ActivityDetailsBinding? = null
private val binding get() = _binding!!
private var url: String? = null
private var title: String? = null
private var content: String? = null
private var youtubeThumbnailImageSrc: String? = null
private var youTubeLink: String? = null
private var youtubeThumbnailImageSetVisibility: Int? = null
private var html: Spannable? = null
private val detailsViewModel: DetailsViewModel by viewModels()
private var postItem: Item? = null
private var postFavoritesSaved = false
private var postFavoritesSavedId = 0
private var menuItem: MenuItem? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
_binding = ActivityDetailsBinding.inflate(layoutInflater)
setContentView(binding.root)
setSupportActionBar(binding.toolbar)
supportActionBar?.setDisplayHomeAsUpEnabled(true)
supportActionBar?.setDisplayShowHomeEnabled(true)
binding.progressBar.visibility = View.VISIBLE
Log.d(
TAG,
"onCreate checkSavedFavoritesItems: $postFavoritesSavedId"
)
postItem = if (intent.extras!!.containsKey("postItem")) {
intent.getParcelableExtra("postItem")!!
} else {
val favoriteItem: FavoritesEntity = intent.getParcelableExtra("favoriteItem")!!
favoriteItem.item
}
}
override fun onDestroy() {
super.onDestroy()
changeMenuItemIcon(menuItem, R.drawable.ic_favorite_border)
binding.fab.setOnClickListener(null)
adRequest = null
_binding = null
}
private fun changeMenuItemIcon(menuItem: MenuItem?, icFavoriteBorder: Int) {
menuItem?.setIcon(icFavoriteBorder)
}
private fun checkSavedFavoritesItems(menuItem: MenuItem?) {
detailsViewModel.favoritesPostList.observe(this) { favoritesEntity ->
try {
favoritesEntity.forEach {
if (it.item.id == postItem?.id) {
changeMenuItemIcon(menuItem, R.drawable.ic_favorite)
postFavoritesSavedId = it.id
Log.d(TAG, "checkSavedFavoritesItems: $postFavoritesSavedId")
postFavoritesSaved = true
}
}
} catch (exception: Exception) {
Log.e(TAG, "checkSavedFavoritesItems: " exception.message)
}
}
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
menuInflater.inflate(R.menu.details_menu, menu)
menuItem = menu.findItem(R.id.action_add_to_favorites)
checkSavedFavoritesItems(menuItem)
return true
}
override fun onOptionsItemSelected(menuItem: MenuItem): Boolean {
when {
menuItem.itemId == R.id.action_add_to_favorites && !postFavoritesSaved -> {
saveTogFavorites(menuItem)
}
menuItem.itemId == R.id.action_add_to_favorites && postFavoritesSaved -> {
removePostFromFavorites(menuItem)
}
menuItem.itemId == android.R.id.home -> this.finish()
}
return super.onOptionsItemSelected(menuItem)
}
private fun saveTogFavorites(menuItem: MenuItem) {
val favoritesEntity = postItem?.let {
FavoritesEntity(0, it)
}
if (favoritesEntity != null) {
detailsViewModel.insertFavorites(favoritesEntity)
}
menuItem.setIcon(R.drawable.ic_favorite)
Snackbar.make(binding.root, "Saved", Snackbar.LENGTH_LONG).show()
postFavoritesSaved = true
}
private fun removePostFromFavorites(menuItem: MenuItem) {
val favoritesEntity = postItem?.let { FavoritesEntity(postFavoritesSavedId, it) }
Log.d(
TAG, "checkSavedFavoritesItems: $postFavoritesSavedId"
)
if (favoritesEntity != null) {
detailsViewModel.deleteFavoritePost(favoritesEntity)
}
menuItem.setIcon(R.drawable.ic_favorite_border)
Snackbar.make(
binding.root,
"Post deleted from favorites", Snackbar.LENGTH_LONG
).show()
postFavoritesSaved = false
}
我嘗試postFavoritesSavedId在日志中檢查并且每次都得到 0，所以我嘗試更改它以獲取專案本身的長 ID 而不是 favoritesEntity 增量 id 但不起作用
uj5u.com熱心網友回復：
checkSavedFavoritesItems在你觀察到的這個方法中，favoritesEntity但你忘記呼叫getFavoritePosts方法，因為這個問題發生了
轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/510179.html