创建适配器对象，找到recycleler view id以设置适配器，然后设置布局管理器。在滚动侦听器中，无法获得正确的LastVisibleItemPosition，它会向我返回-1。 findFirstVisibleItemPosition()也返回-1。
//Here is Adapter
public class CategoryProduct extends RecyclerView.Adapter<RecyclerView.ViewHolder>
`enter code here`{
private static final int ITEM = 0;
private static final int LOADING = 1;
public String vertical = "";
Context context;
private boolean isLoadingAdded = false;
private boolean retryPageLoad = false;
private List<com.example.it.camanagement.model.CategoryProduct> dataSet;
public CategoryProduct(ArrayList<com.example.it.camanagement.model.CategoryProduct> data, Context context, String vertical) {
this.dataSet = data;
this.context = context;
this.vertical = vertical;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
RecyclerView.ViewHolder viewHolder = null;
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (viewType) {
case ITEM:
View viewLoading;
if (vertical.equals("vertical")) {
viewLoading = LayoutInflater.from(parent.getContext())
.inflate(R.layout.category_product_list, parent, false);
} else {
viewLoading = LayoutInflater.from(parent.getContext())
.inflate(R.layout.category_product_list_grid, parent, false);
}
viewHolder = new MyViewHolder(viewLoading);
break;
case LOADING:
View viewLoading1 = inflater.inflate(R.layout.item_progress, parent, false);
viewHolder = new LoadingVH(viewLoading1);
break;
}
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int listPosition) {
if (listPosition == dataSet.size() - 1) {
CategoryDetails categoryDetails = (CategoryDetails) context;
categoryDetails.onBottomReached(listPosition);
}
switch (getItemViewType(listPosition)) {
case ITEM:
final MyViewHolder myViewHolder = (MyViewHolder) holder;
TextView textViewName = myViewHolder.productName;
// TextView textViewVersion = holder.textViewVersion;
ImageView imageView = myViewHolder.productImage;
RatingBar productRating = myViewHolder.productRasting;
TextView productCost = myViewHolder.productCost;
TextView productDiscount = myViewHolder.productDistCount;
TextView productCOLOR = myViewHolder.productColor;
TextView productId = myViewHolder.product_id;
TextView productModel = myViewHolder.productModel;
TextView productQuantity = myViewHolder.productQuantity;
productModel.setText(dataSet.get(listPosition).getModel());
productQuantity.setText(dataSet.get(listPosition).getQuantity());
productId.setText(dataSet.get(listPosition).getProduct_id());
textViewName.setText(dataSet.get(listPosition).getName());
Glide.with(context).load(dataSet.get(listPosition).getImage()).into(imageView);
productRating.setRating(Float.parseFloat(String.valueOf(dataSet.get(listPosition).getRating())));
productCost.setText("RM " + dataSet.get(listPosition).getPrice());
productDiscount.setText(dataSet.get(listPosition).getDiscount());
if (dataSet.get(listPosition).getSpecial().trim().length() != 0) {
myViewHolder.special.setText("RM " + dataSet.get(listPosition).getSpecial());
strikeThroughText(productCost);
}
break;
case LOADING:
LoadingVH loadingVH = (LoadingVH) holder;
if (retryPageLoad) {
loadingVH.mErrorLayout.setVisibility(View.VISIBLE);
loadingVH.mProgressBar.setVisibility(View.GONE);
loadingVH.mErrorTxt.setText(
errorMsg != null ?
errorMsg :
context.getString(R.string.error_msg_unknown));
} else {
loadingVH.mErrorLayout.setVisibility(View.GONE);
loadingVH.mProgressBar.setVisibility(View.VISIBLE);
}
break;
}
}
private void strikeThroughText(TextView price) {
price.setPaintFlags(price.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
}
@Override
public int getItemCount() {
return dataSet == null ? 0 : dataSet.size();
//return dataSet.size();
}
@Override
public int getItemViewType(int position) {
return (position == dataSet.size() - 1 && isLoadingAdded) ? LOADING : ITEM;
}
public com.example.it.camanagement.model.CategoryProduct getItem(int position) {
return dataSet.get(position);
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView productName, productColor, productCost, productDistCount, product_id, productModel, productQuantity, special;
RatingBar productRasting;
ImageView productImage;
public MyViewHolder(View itemView) {
super(itemView);
this.productName = (TextView) itemView.findViewById(R.id.product_name);
this.productColor = (TextView) itemView.findViewById(R.id.product_color);
this.productCost = (TextView) itemView.findViewById(R.id.cost);
this.productDistCount = (TextView) itemView.findViewById(R.id.discount);
this.productRasting = (RatingBar) itemView.findViewById(R.id.product_rating);
this.product_id = (TextView) itemView.findViewById(R.id.product_iid);
this.productQuantity = (TextView) itemView.findViewById(R.id.quantity);
this.productModel = (TextView) itemView.findViewById(R.id.modelProduct);
//this.textViewVersion = (TextView) itemView.findViewById(R.id.textViewVersion);
this.productImage = (ImageView) itemView.findViewById(R.id.product_image);
this.special = (TextView) itemView.findViewById(R.id.special);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Context context = v.getContext();
Intent i = new Intent(context, ProductDescription.class);
i.putExtra("productName", ((TextView) v.findViewById(R.id.product_name)).getText().toString());
i.putExtra("product_id", ((TextView) v.findViewById(R.id.product_iid)).getText().toString());
context.startActivity(i);
if (getPosition() == 0) {
// Toast.makeText(v.getContext(), " On CLick one", Toast.LENGTH_SHORT).show();
}
if (getPosition() == 1) {
//Toast.makeText(v.getContext(), " On CLick Two", Toast.LENGTH_SHORT).show();
}
if (getPosition() == 2) {
// Toast.makeText(v.getContext(), " On CLick Three", Toast.LENGTH_SHORT).show();
}
if (getPosition() == 3) {//
// Toast.makeText(v.getContext(), " On CLick Fore", Toast.LENGTH_SHORT).show();
}
}
});
}
}
protected class LoadingVH extends RecyclerView.ViewHolder {
private ProgressBar mProgressBar;
private ImageButton mRetryBtn;
private TextView mErrorTxt;
private LinearLayout mErrorLayout;
public LoadingVH(View itemView) {
super(itemView);
mProgressBar = (ProgressBar) itemView.findViewById(R.id.loadmore_progress);
mRetryBtn = (ImageButton) itemView.findViewById(R.id.loadmore_retry);
mErrorTxt = (TextView) itemView.findViewById(R.id.loadmore_errortxt);
mErrorLayout = (LinearLayout) itemView.findViewById(R.id.loadmore_errorlayout);
}
}
}
//Recycler View
categoryProduct = (RecyclerView) findViewById(R.id.categoryProductList);
categoryProductAdapter = new CategoryProduct(categoryProduct,categoryProductList, context);
categoryProduct.setAdapter(categoryProductAdapter);
categoryProduct.setNestedScrollingEnabled(false);
categoryProduct.setHasFixedSize(false);
girdLayoutManager = new GridLayoutManager(CategoryDetails.this, 2);
categoryProduct.setLayoutManager(girdLayoutManager);
//scroll Listener
scrollListener = new EndlessRecyclerViewScrollListener(girdLayoutManager) {
@Override
public void onLoadMore(int page, int totalItemsCount, RecyclerView view) {
// Triggered only when new data needs to be appended to the list
// Add whatever code is needed to append new items to the bottom of the list
Log.d("pageCount", "" + page);
Log.d("FirstVisibleITEM", "" + girdLayoutManager.findFirstVisibleItemPosition());
Log.d("LastVisibleITEM", "" + girdLayoutManager.findLastVisibleItemPosition());
}
};
categoryProduct.addOnScrollListener(scrollListener);
答案 0 :(得分：0)
最后解决了它，问题是：我正在创建布局管理器的对象两次。方法中的一个（接收到API响应并通知适配器后）和OnCreate()活动方法中的另一个。从方法中删除一个对象（收到API响应并通知适配器后），修复了问题。