我有30个项目的recyclerview。当我尝试滚动时，分页不起作用。它显示所有项目而不是刷新。下面是我的代码。
public class InstitutesWithSearchActivity extends AppCompatActivity {
PaginationAdapter adapter;
private static final int PAGE_START = 1;
private boolean isLoading, isLastPage = false;
private int TOTAL_PAGES = 2;
int itemCount = 0;
private int currentPage = PAGE_START;
ApiInterface apiInterface;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
adapter = new PaginationAdapter(this);
layoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
recyclerView.addOnScrollListener(new PaginationScrollListener(layoutManager) {
@Override
protected void loadMoreItems() {
isLoading = true;
currentPage += 1;
//mocking network delay for api
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
loadNextPage();
}
},2000);
}
@Override
public int getTotalPageCount() {
return TOTAL_PAGES;
}
@Override
public boolean isLastPage() {
return isLastPage;
}
@Override
public boolean isLoading() {
return isLoading;
}
});
//init service and load data
apiInterface = ApiClient.getClient().create(ApiInterface.class);
loadFirstPage();
}
private void loadNextPage() {
Call<InstituteResponseModel> call = apiInterface.masterInstitutes();
call.enqueue(new Callback<InstituteResponseModel>() {
@Override
public void onResponse(Call<InstituteResponseModel> call, Response<InstituteResponseModel> response) {
adapter.removeLoadingFooter();
isLoading = false;
ArrayList<InstituteModel> results = fetchResults(response);
adapter.addAll(results);
if (currentPage != PAGE_START) adapter.removeLoadingFooter();
adapter.addAll(results);
if (currentPage < TOTAL_PAGES) adapter.addLoadingFooter();
else isLastPage = true;
isLoading = false;
}
@Override
public void onFailure(Call<InstituteResponseModel> call, Throwable t) {
t.printStackTrace();
}
});
}
private void loadFirstPage() {
Log.e(TAG,"loadFirstPage");
Call<InstituteResponseModel> call = apiInterface.masterInstitutes();
call.enqueue(new Callback<InstituteResponseModel>() {
@Override
public void onResponse(Call<InstituteResponseModel> call, Response<InstituteResponseModel> response) {
ArrayList<InstituteModel> results = fetchResults(response);
progressBar.setVisibility(View.GONE);
adapter.addAll(results);
if (currentPage <= TOTAL_PAGES) adapter.addLoadingFooter();
else isLastPage = true;
}
@Override
public void onFailure(Call<InstituteResponseModel> call, Throwable t) {
t.printStackTrace();
}
});
}
private ArrayList<InstituteModel> fetchResults(Response<InstituteResponseModel> response) {
InstituteResponseModel responseModel = response.body();
return responseModel.getData();
}
}
我不知道我这边有什么错误。我是这个分页概念的新手。我正在获取使用forloop显示数据的示例代码。我正在使用API在Recyclerview中显示数据。
公共类PaginationAdapter扩展了RecyclerView.Adapter {
private static final int ITEM = 0;
private static final int LOADING = 1;
boolean isLoadingAdded = false;
private ArrayList<InstituteModel> modelArrayList;
Context context;
public PaginationAdapter(Context context) {
this.context = context;
modelArrayList = new ArrayList<>();
}
public ArrayList<InstituteModel> getInstitutes() {
return modelArrayList;
}
public void setInstitutes(ArrayList<InstituteModel> modelArrayList) {
this.modelArrayList = modelArrayList;
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
RecyclerView.ViewHolder viewHolder = null;
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (viewType){
case ITEM:
viewHolder = getViewHolder(parent, inflater);
break;
case LOADING:
View v2 = inflater.inflate(R.layout.item_progress, parent, false);
viewHolder = new LoadingVH(v2);
break;
}
return viewHolder;
}
private RecyclerView.ViewHolder getViewHolder(ViewGroup parent, LayoutInflater inflater){
RecyclerView.ViewHolder viewHolder;
View v1 = inflater.inflate(R.layout.institute_row_layout, parent, false);
viewHolder = new InstituteHolder(v1);
return viewHolder;
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int parent) {
InstituteModel model = modelArrayList.get(parent);
switch (getItemViewType(parent)){
case ITEM:
final InstituteHolder instituteHolder = (InstituteHolder) holder;
instituteHolder.instName.setText(model.getInstituteName());
Glide.with(context)
.load(model.getImageURL())
.listener(new RequestListener<String, GlideDrawable>() {
@Override
public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {
instituteHolder.progressBar.setVisibility(GONE);
return false;
}
@Override
public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
instituteHolder.progressBar.setVisibility(GONE);
return false;
}
})
.diskCacheStrategy(DiskCacheStrategy.ALL)
.centerCrop()
.crossFade()
.into(instituteHolder.instImg);
break;
case LOADING:
break;
}
}
@Override
public int getItemCount() {
return modelArrayList == null ? 0 : modelArrayList.size();
}
@Override
public int getItemViewType(int position) {
return (position == modelArrayList.size()-1 && isLoadingAdded) ? LOADING : ITEM;
}
public void add(InstituteModel m){
modelArrayList.add(m);
notifyItemInserted(modelArrayList.size()-1);
}
public void addAll(ArrayList<InstituteModel> modelsList){
for (InstituteModel model : modelsList){
add(model);
}
}
public void remove(InstituteModel model){
int position = modelArrayList.indexOf(model);
if (position > -1){
modelArrayList.remove(position);
notifyItemRemoved(position);
}
}
public void clear(){
isLoadingAdded = false;
while (getItemCount()>0){
remove(getItem(0));
}
}
public boolean isEmpty(){
return getItemCount() == 0;
}
public void addLoadingFooter(){
isLoadingAdded = true;
add(new InstituteModel());
}
public void removeLoadingFooter(){
isLoadingAdded = false;
int position = modelArrayList.size() -1;
InstituteModel result = getItem(position);
if (result != null){
modelArrayList.remove(position);
notifyItemRemoved(position);
}
}
public InstituteModel getItem(int position){return modelArrayList.get(position);}
protected class InstituteHolder extends RecyclerView.ViewHolder {
TextView instName;
ImageView instImg;
TextView cityName, areaName;
RelativeLayout cardView;
ProgressBar progressBar;
public InstituteHolder(@NonNull View itemView) {
super(itemView);
instImg = itemView.findViewById(R.id.course_image);
instName = itemView.findViewById(R.id.course_name);
areaName = itemView.findViewById(R.id.course_area);
cityName = itemView.findViewById(R.id.course_city);
progressBar = itemView.findViewById(R.id.imgProgress);
cardView = itemView.findViewById(R.id.cardView);
}
}
protected class LoadingVH extends RecyclerView.ViewHolder {
public LoadingVH(@NonNull View itemView) {
super(itemView);
}
}
}