我正在从Firestore提取数据并将其显示在具有2种不同布局的recyclerview中。就其本身而言，它可以正常工作。但是，当我添加第三个布局时，仅在提取数据时填充了进度条，回收器视图完全停止工作。我正在努力实现这一目标：http://www.androidlearningtutorials.com/blog_details.php?article_id=12
这是我的适配器：
public class MenuItemAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
private ArrayList<MenuItem> menuItemArrayList;
public HashMap<String, Integer> selectionItemsHashMap;
private LinearLayoutManager linearLayoutManager;
private Context adapterContext;
private static final String TAG = MenuItemAdapter.class.getSimpleName();
// The minimum amount of items to have below your current scroll position
// before loading more.
private boolean isLoading;
private int visibleThreshold = 5;
private int lastVisibleItem, totalItemCount;
private OnAddToCartListener addToCartListener;
private OnLoadMoreListener onLoadMoreListener; // create listener variable
public interface OnLoadMoreListener { // define listener interface
void onLoadMore();
}
public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) {
this.onLoadMoreListener = onLoadMoreListener;
}
public interface OnAddToCartListener {
void onAddToCart(HashMap<String, Integer> selectionItemsHashMap);
}
public void setOnAddToCartListener(OnAddToCartListener addToCartListener) {
this.addToCartListener = addToCartListener;
}
// Constructor class
public MenuItemAdapter(Context adapterContext, ArrayList<MenuItem> menuItemArrayList, HashMap<String, Integer> selectionItemsHashMap, RecyclerView menuRecycler) {
this.adapterContext = adapterContext;
this.menuItemArrayList = menuItemArrayList;
this.selectionItemsHashMap = selectionItemsHashMap;
// Load more on scrolling
linearLayoutManager = (LinearLayoutManager) menuRecycler.getLayoutManager();
menuRecycler.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
if (!isLoading && totalItemCount <= (lastVisibleItem + visibleThreshold)) {
if (onLoadMoreListener != null) {
onLoadMoreListener.onLoadMore();
}
isLoading = true;
}
}
});
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
final RecyclerView.ViewHolder holder;
View view;
switch (viewType) {
case R.layout.menu_item_card:
view = LayoutInflater.from(adapterContext).inflate(R.layout.menu_item_card, viewGroup, false);
holder = new DishViewHolder(view);
break;
case R.layout.section_header:
view = LayoutInflater.from(adapterContext).inflate(R.layout.section_header, viewGroup, false);
holder = new SectionViewHolder(view);
break;
case R.layout.item_loading:
view = LayoutInflater.from(adapterContext).inflate(R.layout.item_loading, viewGroup, false);
holder = new LoadViewHolder(view);
break;
default:
view = LayoutInflater.from(adapterContext).inflate(R.layout.item_loading, viewGroup, false);
holder = new LoadViewHolder(view);
break;
}
return holder;
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int i) {
if (holder instanceof SectionViewHolder) {
((SectionViewHolder)holder).tvHeaderName.setText(menuItemArrayList.get(i).getHeaderName());
((SectionViewHolder)holder).tvHeaderDescription.setText(menuItemArrayList.get(i).getHeaderDescription());
} else if (holder instanceof DishViewHolder) {
((DishViewHolder)holder).tvMenuItemPrice.setText("$"+menuItemArrayList.get(i).getMenuItemPrice());
((DishViewHolder)holder).tvMenuItemName.setText(menuItemArrayList.get(i).getMenuItemName());
((DishViewHolder)holder).tvMenuItemDescription.setText(menuItemArrayList.get(i).getMenuItemDescription());
Glide.with(adapterContext).load(menuItemArrayList.get(i).getMenuItemImage()).placeholder(R.drawable.menu_card_default).into(((DishViewHolder) holder).ivMenuItemImage);
} else if (holder instanceof LoadViewHolder) {
((LoadViewHolder)holder).progressBar.setIndeterminate(true);
}
}
@Override
public int getItemCount() {
return menuItemArrayList.size();
}
@Override
public int getItemViewType(int position) {
int levelCode = Integer.parseInt(menuItemArrayList.get(position).getLevelCode());
if (menuItemArrayList.get(position) != null) {
if (levelCode % 2 == 0) {
return R.layout.menu_item_card;
} else {
return R.layout.section_header;
}
}
else {
return R.layout.item_loading;
}
}
private void showToast(View parent) {
LayoutInflater inflater = (LayoutInflater) adapterContext.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
View view = inflater.inflate(R.layout.toast_add_cart, (ViewGroup) parent.findViewById(R.id.toast_root));
Toast toast = new Toast(adapterContext);
toast.setGravity(Gravity.CENTER_VERTICAL, 0,600);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(view);
toast.show();
}
public void setLoaded() {
isLoading = false;
}
public class DishViewHolder extends RecyclerView.ViewHolder{
public TextView tvMenuItemName, tvMenuItemDescription, tvMenuItemPrice;
public ImageView ivMenuItemImage;
public Button btnInitialAdd;
public DishViewHolder(@NonNull View itemView) {
super(itemView);
tvMenuItemName = itemView.findViewById(R.id.menu_item_name);
tvMenuItemDescription = itemView.findViewById(R.id.menu_item_description);
ivMenuItemImage = itemView.findViewById(R.id.image_menu_item);
tvMenuItemPrice = itemView.findViewById(R.id.menu_item_price);
btnInitialAdd = itemView.findViewById(R.id.button_initial_add);
btnInitialAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int position = getAdapterPosition();
String itemNameCheck = menuItemArrayList.get(position).getMenuItemName();
if (selectionItemsHashMap != null) {
if (selectionItemsHashMap.containsKey(itemNameCheck)) {
int currentQuantity = selectionItemsHashMap.get(itemNameCheck);
currentQuantity++;
selectionItemsHashMap.put(itemNameCheck,currentQuantity);
} else {
selectionItemsHashMap.put(menuItemArrayList.get(position).getMenuItemName(), 1);
}
} else {
selectionItemsHashMap = new HashMap<String, Integer>();
selectionItemsHashMap.put(menuItemArrayList.get(position).getMenuItemName(), 1);
}
addToCartListener.onAddToCart(selectionItemsHashMap);
showToast(view);
}
});
}
}
public class SectionViewHolder extends RecyclerView.ViewHolder {
public TextView tvHeaderName, tvHeaderDescription;
public SectionViewHolder(@NonNull View itemView) {
super(itemView);
tvHeaderName = itemView.findViewById(R.id.section_header_name);
tvHeaderDescription = itemView.findViewById(R.id.section_header_description);
}
}
public class LoadViewHolder extends RecyclerView.ViewHolder {
public ProgressBar progressBar;
public LoadViewHolder(@NonNull View itemView) {
super(itemView);
progressBar = itemView.findViewById(R.id.progress_bar);
}
}
}
这是我主要片段中的相关代码：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
menuView = inflater.inflate(R.layout.fragment_menu, container, false);
Button backButton = menuView.findViewById(R.id.button_back);
Button nextButton = menuView.findViewById(R.id.button_next);
tvTotalAmount = menuView.findViewById(R.id.total_amount);
bundle = getArguments();
db = FirebaseFirestore.getInstance();
menuItemArrayList = new ArrayList<>();
bundle = getArguments();
// Get data
if (bundle != null && bundle.containsKey("restaurantId") && bundle.containsKey("restaurantPath")) {
restaurantPath = bundle.getString("restaurantPath");
restaurantId = bundle.getString("restaurantId");
if (bundle.containsKey("cartContent")) {
Serializable storedCart = bundle.getSerializable("cartContent");
cartItemsHashmap = (HashMap<String, Integer>) storedCart;
reinstateCart();
} else {
cartItemsHashmap = null;
}
}
restaurantHeader();
setupMenuRecycler();
lastResult = null;
if (menuItemArrayList.size() > 0) {
menuItemArrayList.clear();
}
fetchData();
// Setup recycler
menuItemAdapter = new MenuItemAdapter(menuContext, menuItemArrayList, cartItemsHashmap, menuRecycler);
menuRecycler.setAdapter(menuItemAdapter);
// Load more
menuItemAdapter.setOnLoadMoreListener(new MenuItemAdapter.OnLoadMoreListener() {
@Override
public void onLoadMore() {
if (menuItemArrayList.size() < 3) {
menuItemArrayList.add(null);
menuItemAdapter.notifyItemInserted(menuItemArrayList.size() - 1);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
menuItemArrayList.remove(menuItemArrayList.size() - 1);
menuItemAdapter.notifyItemRemoved(menuItemArrayList.size());
// Fetch more data
fetchData();
menuItemAdapter.notifyDataSetChanged();
menuItemAdapter.setLoaded();
}
}, 400);
}
}
});
// Using the adapter interface to add items to cart and adding up total amount
menuItemAdapter.setOnAddToCartListener(new MenuItemAdapter.OnAddToCartListener() {
@Override
public void onAddToCart(final HashMap selectionItemsHashMap) {
OnUpdateCartListener onUpdateCartListener = new OnUpdateCartListener() {
@Override
public int getAmount() {
return totalAmount;
}
@Override
public void onUpdateCart(int totalAmount) {
String stringTotalAmount = Integer.toString(totalAmount);
tvTotalAmount.setText(stringTotalAmount);
finalTotalAmount = totalAmount;
}
};
setupSelectionRecycler(menuView);
totalAmount = mapToArray(selectionItemsHashMap);
if (cartItemsHashmap==null) {
selectionAdapter = new SelectionAdapter(selectionItemArrayList, selectionItemsHashMap, totalAmount, onUpdateCartListener);
} else {
selectionAdapter = new SelectionAdapter(selectionItemArrayList, cartItemsHashmap, totalAmount, onUpdateCartListener);
}
selectionRecycler.setAdapter(selectionAdapter);
cartItemsHashmap = selectionItemsHashMap;
selectionAdapter.setUpdateCartListener(new SelectionAdapter.OnUpdateCartListener() {
@Override
public void onUpdateCart(int totalAmount) {
String stringTotalAmount = Integer.toString(totalAmount);
tvTotalAmount.setText(stringTotalAmount);
finalTotalAmount = totalAmount;
}
});
}
});
backButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
bundle.putBoolean("direction", false);
bundle.remove("cartContent");
bundle.remove("cartSum");
cartFilledListener.onCartFilled(bundle);
}
});
nextButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int sentTotalAmount = Integer.parseInt(tvTotalAmount.getText().toString());
if (sentTotalAmount > 0) {
bundle.putSerializable("cartContent", cartItemsHashmap);
Log.d(TAG, "cart content:" + cartItemsHashmap);
bundle.putInt("cartSum", sentTotalAmount);
bundle.putBoolean("direction", true);
cartFilledListener.onCartFilled(bundle);
} else {
showToast(view);
}
}
});
return menuView;
}
private void fetchData() {
if (lastResult == null) {
menuQuery = db.collection(restaurantPath).orderBy("levelCode", Query.Direction.ASCENDING).limit(3);
} else {
menuQuery = db.collection(restaurantPath).orderBy("levelCode", Query.Direction.ASCENDING).limit(3).startAfter(lastResult);
}
menuQuery.get().addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
@Override
public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
for (QueryDocumentSnapshot documentSnapshot : queryDocumentSnapshots) {
MenuItem menuItems = new MenuItem(documentSnapshot.getString("menuItemDescription"),
documentSnapshot.getString("menuItemName"),
documentSnapshot.getString("levelCode"),
documentSnapshot.getString("menuItemImage"),
documentSnapshot.getString("headerName"),
documentSnapshot.getString("menuItemPrice"),
documentSnapshot.getString("headerDescription"));
menuItemArrayList.add(menuItems);
}
if (queryDocumentSnapshots.size() > 0) {
lastResult = queryDocumentSnapshots.getDocuments().get(queryDocumentSnapshots.size() - 1);
}
}
});
}
这是请求的堆栈跟踪；我之前收到过跳过布局的消息，但是回收站工作得很好：
06-03 00:56:08.022 31054-31054/com.bvb09.shoppingcart E/RecyclerView: No adapter attached; skipping layout
06-03 00:56:08.742 1471-1471/? D/StatusBar.NetworkController: refreshViews connected={ wifi } level=0 combinedSignalIconId=0x7f020649/com.android.systemui:drawable/stat_sys_wifi_signal_4 mobileLabel= wifiLabel="MVP Factory" emergencyOnly=false combinedLabel="MVP Factory" mAirplaneMode=true mDataActivity=0 mPhoneSignalIconId=0x0/(null) mQSPhoneSignalIconId=0x0/(null) mDataDirectionIconId=0x0/(null) mDataSignalIconId=0x0/(null) mDataTypeIconId=0x0/(null) mQSDataTypeIconId=0x0/(null) mNoSimIconId=0x0/(null) mWifiIconId=0x7f020649/com.android.systemui:drawable/stat_sys_wifi_signal_4 mQSWifiIconId=0x7f02032b/com.android.systemui:drawable/qs_tile_wifi_signal_4 mWifiActivityIconId=0x7f0205fc/com.android.systemui:drawable/stat_sys_signal_inout mBluetoothTetherIconId=0x7f020625/com.android.systemui:drawable/stat_sys_tether_bluetooth
06-03 00:56:08.742 1471-1471/? D/StatusBar.NetworkController: refreshNwBoosterIndicator - setNWBoosterIndicators(false)
06-03 00:56:08.752 1471-1471/? D/StatusBar.NetworkController: refreshNwBoosterIndicator - setNWBoosterIndicators(false)
06-03 00:56:08.752 1471-1471/? D/StatusBar.NetworkController: refreshNwBoosterIndicator - setNWBoosterIndicators(false)
06-03 00:56:08.752 1471-1471/? D/StatusBar.NetworkController: refreshNwBoosterIndicator - setNWBoosterIndicators(false)
06-03 00:56:08.992 31943-31943/? E/TZ_CCM_SERVER: Only 'CCM' are supported
06-03 00:56:08.992 31943-31943/? I/TZ_CCM_SERVER: ###Exit TZ CCM Server
06-03 00:56:08.992 889-1664/? E/Watchdog: !@Sync 10961 [06-03 00:56:08.997]