我在RecyclerView上有一个项目列表，当您选择“ onLongclick”项目时，项目名称上方会出现删除线。 我的问题是，当我删除项目（并调用notifyDataSetChanged（））时，删除线仍保留在与删除的上一个项目完全相同的行中，但是现在删除了一个新项目。例如：
我的列表在删除项目之前
我的列表项目删除后
当我离开页面并重新打开它时，项目将正确显示，没有出现不需要的删除线，这在我的代码中已经确定，但是我不知道如何在第一次删除删除线时执行此操作。我是应用程序开发的新手，但我感觉我只是想念一个显而易见的解决方案而已，也许不愿意……在此先感谢您。
P.s。我的理解是，即使数据发生更改，删除线仍会保留在完全相同的recycleViewHolder上，但是我不确定在不关闭和打开活动的情况下如何撤消删除线。
class ListRecyclerViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
public TextView nameView;
public TextView categoryView;
private ItemClickListener itemClickListener;
public ListRecyclerViewHolder(@NonNull View itemView) {
super(itemView);
nameView = itemView.findViewById(R.id.li_name_view);
categoryView = itemView.findViewById(R.id.li_category_view);
itemView.setOnClickListener(this);
itemView.setOnLongClickListener(this);
}
public void setItemClickListener(ItemClickListener itemClickListener){
this.itemClickListener = itemClickListener;
}
@Override
public void onClick(View v) {
itemClickListener.Onclick(v,getAdapterPosition(),false);
}
@Override
public boolean onLongClick(View v) {
itemClickListener.Onclick(v,getAdapterPosition(),true);
return true;
}
public void SetStrike(TextView text,boolean strike){
if (strike) {
text.setPaintFlags(text.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
text.setTextColor(Color.GRAY);
} else {
text.setPaintFlags(text.getPaintFlags() & ~Paint.STRIKE_THRU_TEXT_FLAG);
text.setTextColor(Color.BLACK);
}
}
}
public class ListItemAdaptor extends RecyclerView.Adapter<ListRecyclerViewHolder> {
private List<Inventory> mAllItems = new ArrayList<>();
public Context context;
public int selectedItem;
private List<Inventory> allCrossedItemsOnList = new ArrayList<Inventory>();
private boolean checkIfEmpty = false;
public void setItemsAdaptor(List<Inventory> allItems,Context context){
if(allItems.isEmpty() || allItems == null)
{
//No item in the list
Inventory item = new Inventory();
item.setName("List Empty!");
item.setCategory("");
allItems.add(item);
this.mAllItems = allItems;
this.context = context;
this.allCrossedItemsOnList = null;
checkIfEmpty = true;
//when called this updates all items displayed on the list.
this.notifyDataSetChanged();
return;
}
this.mAllItems = allItems;
this.context = context;
this.allCrossedItemsOnList = FindAllCrossedItems();
checkIfEmpty = false;
//when called this updates all items displayed on the list.
notifyDataSetChanged();
Log.d("TAG","Data Updated Adaptor");
}
@NonNull
@Override
public ListRecyclerViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View itemView = inflater.inflate(R.layout.list_item_tab,viewGroup, false);
return new ListRecyclerViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull final ListRecyclerViewHolder recyclerViewHolder, int i) {
recyclerViewHolder.nameView.setText(mAllItems.get(i).getName());
recyclerViewHolder.categoryView.setText(mAllItems.get(i).getCategory());
//Set the item if they are crossed or not when page is opened.
if(!checkIfEmpty && allCrossedItemsOnList != null){
for (Inventory item: allCrossedItemsOnList){
if(mAllItems.get(i).getId() == item.getId()){
recyclerViewHolder.SetStrike(recyclerViewHolder.nameView,true);
}
}
}
else if (!checkIfEmpty && recyclerViewHolder.nameView.getPaint().isStrikeThruText()) {
recyclerViewHolder.SetStrike(recyclerViewHolder.nameView,false);
}
recyclerViewHolder.setItemClickListener(new ItemClickListener() {
@Override
public void Onclick(View view, int position, boolean isLongClicked) {
if (!checkIfEmpty) {
if (isLongClicked) {
Toast.makeText(context, "Selected: " + mAllItems.get(position).getName(), Toast.LENGTH_SHORT).show();
//selectedItem = position;
if (!recyclerViewHolder.nameView.getPaint().isStrikeThruText()) {
recyclerViewHolder.SetStrike(recyclerViewHolder.nameView,true);
allCrossedItemsOnList.add(mAllItems.get(position));
mAllItems.get(position).setCrossedOnList(true);
MainActivity.myAppLocalDatabase.myDao().updateItem(mAllItems.get(position));
} else {
recyclerViewHolder.SetStrike(recyclerViewHolder.nameView,false);
allCrossedItemsOnList.remove(mAllItems.get(position));
mAllItems.get(position).setCrossedOnList(false);
MainActivity.myAppLocalDatabase.myDao().updateItem(mAllItems.get(position));
}
} else {
Toast.makeText(context, "Clicked: " + mAllItems.get(position).getName(), Toast.LENGTH_SHORT).show();
}
}
}
});
}
@Override
public int getItemCount() {
return mAllItems.size();
}
public int getSelectedItem(){return selectedItem;}
public List<Inventory> getCrossedItems(){return allCrossedItemsOnList;}
public void setCrossedItems(List<Inventory> crossed) {
this.allCrossedItemsOnList = crossed;
}
//When page opened checks items (my data set) for which items are crossed already.
private List<Inventory> FindAllCrossedItems(){
List<Inventory> itemsCrossed = new ArrayList<Inventory>();
for(Inventory item : mAllItems)
{
if (item.isCrossedOnList()) {
itemsCrossed.add(item);
}
}
return itemsCrossed;
}
//Updated database of all the crossed out items on the list that have been deleted.
public void RemoveAllCrossedItems(){
for (Inventory item: allCrossedItemsOnList) {
Log.d("TAG","To be removed "+item.getName());
item.setCrossedOnList(false);
item.setAddToList(false);
MainActivity.myAppLocalDatabase.myDao().updateItem(item);
}
}
}