我有这种奇怪的行为，其中 onItemAtEndLoaded 在 onZeroItemsLoaded 之后被触发，因此回收器视图继续加载并且不会停止。我在 GitHub 上有这个项目，有人可以帮帮我吗，我花了几天时间。有人可以看看吗？
https://github.com/JosePedroNobre/ProductHunter
这是我的 BoundaryCall 课程
class RepoBoundaryCallback(private val day:String,
private val service: PHService,
private val cache:PHLocalCache) : PagedList.BoundaryCallback<Post>() {
// keep the last requested page.
// When the request is successful, increment the page number.
private var lastRequestedPage = 1
private val _networkErrors = MutableLiveData<String>()
// LiveData of network errors.
val networkErrors: LiveData<String>
get() = _networkErrors
// avoid triggering multiple requests in the same time
private var isRequestInProgress = false
/**
* This method is called at the very beggining
*/
override fun onZeroItemsLoaded() {
requestAndSaveData()
}
/**
* This method will tell when the user reached the end of the recycler view
*/
override fun onItemAtEndLoaded(itemAtEnd: Post) {
requestAndSaveData()
//TODO resolver este bug
//ele aqui sabe que chegou ao fim , o problema desta API é que nao dá o total de páginas
// e quando ultrapassa as paginas que deve ela dá dados repetidos
// como o onConflit está replace ele está sempre a substituir os items e sempre a actualizar
}
/**
* Requests data from the API and increment the page in case of success
* Save the fetched data into the database to allow offline usage
*/
private fun requestAndSaveData(){
//TODO ao atingir o total de páginas o isRequestInProgress estará a null(o problema de estar sempre a actualizar vem daqui)
if (isRequestInProgress) return
isRequestInProgress = true
getPosts(service,day,lastRequestedPage,BuildConfig.API_KEY, NETWORK_PAGE_SIZE,{ repos ->
cache.insert(repos){
lastRequestedPage++
isRequestInProgress = false
}
},{error ->
_networkErrors
isRequestInProgress = false
})
}
/**
* static block to have the page size to the network calls
*/
companion object {
private const val NETWORK_PAGE_SIZE = 10
}
}
这是我的基于分页的适配器
abstract class BasePagedAdapter<T>(diffCallBack: DiffUtil.ItemCallback<T>) : PagedListAdapter<T, RecyclerView.ViewHolder>(diffCallBack){
@LayoutRes abstract fun layoutToInflate(viewType: Int): Int
abstract fun defineViewHolder(viewType: Int, view: View) : RecyclerView.ViewHolder
abstract fun doOnBindViewHolder(holder: RecyclerView.ViewHolder, item: T?, position: Int)
final override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
val view = LayoutInflater.from(parent.context).inflate(layoutToInflate(viewType), parent, false)
return defineViewHolder(viewType, view)
}
final override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
doOnBindViewHolder(holder, getItem(position), position)
}
fun retrieveItem(position: Int) = getItem(position)
}
这是我的适配器和 ViewHolder
class PostAdapter : BasePagedAdapter<Post>(diffCallBack) {
override fun layoutToInflate(viewType: Int) = R.layout.item_post
override fun defineViewHolder(viewType: Int, view: View) = PostViewHolder(view)
override fun doOnBindViewHolder(holder: RecyclerView.ViewHolder, item: Post?, position: Int){
when(holder){
is PostViewHolder ->{
holder.setup(item)
}
}
}
/**
* Its the first thing to start(like a static block in java)
*/
companion object {
val diffCallBack = PostDiffCallback()
}
class PostViewHolder(view: View) : RecyclerView.ViewHolder(view){
private var dataBindig: ItemPostBinding = DataBindingUtil.bind(view)!!
fun setup(item: Post?){
/**
* Variables defined in item_post.xml
*/
dataBindig.title = item?.productName
dataBindig.description = item?.tagline
dataBindig.commentCountBinding = item?.commentsCount.toString()
dataBindig.upvotes = item?.votesCount.toString()
dataBindig.productImage = item?.postImage?.productLargeImgUrl
dataBindig.userImage = item?.user?.imageUrl?.userLargeImgUrl
dataBindig.userName = item?.user?.name
if(diffCallBack.areContentsTheSame(item,item)){
//TODO stop incrementing the page and stop all requests
}
}
}
}