在分页 3 android 中到达页面末尾时分页不起作用？

Question

VideoStatusDataSource.kt

class VideoStatusDataSource(
        private val categoryKey: String,
        private val videosStatusApi: VideoStatusApiService
    ) : PagingSource<Int, VideoStatus>() {
    
    
        companion object {
            private const val VIDEO_STARTING_PAGE_INDEX = 0
        }
    
        override suspend fun load(params: LoadParams<Int>): LoadResult<Int, VideoStatus> {
            return try {
    
                val pageIndex = params.key ?: VIDEO_STARTING_PAGE_INDEX
                logger(params.key)
                logger(pageIndex)
                val response =
                    videosStatusApi.getVideoStatusByPageNumberAndCategoryName(pageIndex, categoryKey)
    
                val jsonCategoryResponse = response.getAsJsonArray(DATA_KEY)
                val videoStatusList: List<VideoStatus> = Gson().fromJson(jsonCategoryResponse)
    
                LoadResult.Page(
                    data = videoStatusList.orEmpty(),
                    prevKey = if (pageIndex == VIDEO_STARTING_PAGE_INDEX) null else pageIndex - 1,
                    nextKey = if (videoStatusList.isEmpty()) null else pageIndex.plus(1)
                )
    
            } catch (exception: IOException) {
                LoadResult.Error(exception)
            } catch (exception: HttpException) {
                LoadResult.Error(exception)
            } catch (exception: Exception) {
                LoadResult.Error(exception)
            }
        }
    
        override fun getRefreshKey(state: PagingState<Int, VideoStatus>): Int? {
            return state.anchorPosition?.let { anchorPosition ->
                val anchorPage = state.closestPageToPosition(anchorPosition)
                anchorPage?.prevKey?.plus(1) ?: anchorPage?.nextKey?.minus(1)
            }
        }

}

video-API 服务在每个页面上提供 10 个结果，但使用此数据源 class 它会立即加载所有数据我只想最初加载前 10 个项目，然后使用滚动前 10 个项目来加载接下来的 10 个项目这是我的分页数据存储库

MainRepopsitory.kt

fun getVideoStatusPagingData(categoryKey: String): Pager<Int, VideoStatus> =
    Pager(
        config = PagingConfig(
            pageSize = 10
        ),
        pagingSourceFactory = { VideoStatusDataSource(categoryKey, videosStatusApi) }
    )

视图模型

@HiltViewModel
class PagingViewModel @Inject constructor(
    private val mainRepository: MainRepository,
    @IoDispatcher private val ioDispatcher: CoroutineDispatcher
) : ViewModel() {


    fun getCurrentCategoryVideoStatus(categoryKey: String): Flow<PagingData<VideoStatus>> =
        mainRepository
            .getVideoStatusPagingData(categoryKey)
            .flow.cachedIn(viewModelScope)
            .flowOn(ioDispatcher)


}

Answer 1

这就是我在分页源中使用加载函数的方式你可以从中获得帮助我的应用程序中有五到六个分页源，并且都具有与此相同的实现

override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Message> {
return try {
            val nextPage = params.key ?: 0
            chatWithSellerRequest.offset = nextPage.times(PAGE_SIZE_LIMIT)
            val response = apiService.getSellerChatResponse(chatWithSellerRequest)
            _chatWithSellerResultResponse.value = response.chatWithSellerResult

            LoadResult.Page(
                data = response.chatWithSellerResult?.messages!!,
                prevKey = null,
                nextKey = if (response.chatWithSellerResult.messages.isEmpty()) null else nextPage + 1
            )
        } catch (e: Exception) {
            LoadResult.Error(e)
        }

在分页 3 android 中到达页面末尾时分页不起作用？

pagination not working when reaches to end of page in paging 3 android?

pagination

android

json

datasource

kotlin