如何获取recyclerview Item位置的文档id？

我正在使用firebaseUI使用库来填充回收器视图firestore数据库。 当我尝试检索时文档编号当我点击回收器查看项目时，它是这样的

 DocumentSnapshot snapshot = getSnapshots()
              .getSnapshot(holder.getAdapterPosition());
          final String countryName = snapshot.getId();

我试过这个代码但是getSnapshots()出现红色字，但内部不起作用onbindeviewolder所以我尝试了这个但也不起作用

DocumentReference aa=firebaseFirestore.collection("MainCategories").document(String.valueOf(SS));
            String aaa=aa.getId();

那么有没有什么方法可以检索文档ID，因为上面的代码不在这里工作

 private class CategoriesAdapter extends RecyclerView.Adapter<AllCategoriesViewHolder> {
         private List<mainCategroies> categorylist;

         CategoriesAdapter(List<mainCategroies> categorylist) {
              this.categorylist = categorylist;

         }

         @NonNull
         @Override
         public AllCategoriesViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
              View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview_maincategory, parent, false);
              return new AllCategoriesViewHolder(view);
         }

         @Override
         public void onBindViewHolder(@NonNull final AllCategoriesViewHolder holder, int position) {
              final String categoryName = categorylist.get(position).getCategory_Name();
              holder.setCategory_Name(categoryName);
              String d = categorylist.get(position).getImageUrl();
              holder.setImageUrl(d);

              MainActivityProgress.setVisibility(View.GONE);
              holder.view.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {



              }
              });

         }

         @Override
         public int getItemCount() {
              return categorylist.size();
         }
         }

持有者阶层

私有类 AllCategoriesViewHolder 扩展 RecyclerView.ViewHolder { 私人景观；

 public AllCategoriesViewHolder(final View itemView) {
      super(itemView);
      view = itemView;

 }

 void setCategory_Name(String category_Name) {
      TextView names = view.findViewById(R.id.CategoryName);
      names.setText(category_Name);

 }


 void setImageUrl(String imageUrl) {
      ImageView imageView = view.findViewById(R.id.MainCat_CardViewImage);
      Picasso.get()
     .load(imageUrl)
     .fit()
     .into(imageView);
 }
 }

和模型类

public class CountryItem {
     private String CountryName;
public CountryItem(){

}
     public CountryItem(String countryName) {
     CountryName = countryName;
     }

     public String getCountryName() {
     return CountryName;
     }

     public void setCountryName(String countryName) {
     CountryName = countryName;
     }
}

您尝试获取项目的 uid 的方法，即：

DocumentSnapshot snapshot = getSnapshots().getSnapshot(holder.getAdapterPosition());
final String countryName = snapshot.getId();

仅在以下情况下才有效FirestoreRecyclerAdapter。当您使用RecyclerView.Adapter您必须在模型类中添加 uid，然后检索它。

CountryItem.类

public class CountryItem {
    private String CountryName;
    private String uid;
   //add getters and setters
}

从 firestore 检索数据时，将 uid 字段添加到您的对象中。我假设您正在为此使用查询，那么它会像：-

Query query = firestore.collection("Collection").orderBy("CountryName",Query.Direction.ASCENDING);

query.addSnapshotListener(this, new EventListener<QuerySnapshot>() {
    @Override
    public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {
        for(DocumentSnapshot documentSnapshot: documentSnapshots) {
            CountryItem countryItem = documentSnapshot.toObject(CountryItem.class);

             countryItem.setuid(documentSnapshot.getId().toString());
             countryItemList.add(countryItem);
        }
    }

});

And onClick您可以获取某个项目的 uid 并将其传递给您的方法：-

holder.view.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        String uid = categorylist.get(position).getUid();

     }
});