Firestore与RecyclerView数据同步：精细化刷新控制策略

public class CustomStudentAdapter extends RecyclerView.Adapter<CustomStudentAdapter.StudentViewHolder> {

    private List<Student> studentList;
    private Context context;

    public CustomStudentAdapter(Context context) {
        this.context = context;
        this.studentList = new ArrayList<>();
    }

    public void setStudentList(List<Student> newStudents) {
        this.studentList.clear();
        this.studentList.addAll(newStudents);
        notifyDataSetChanged(); // 全量刷新，但仅在数据加载时发生
    }

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

    @Override
    public void onBindViewHolder(@NonNull StudentViewHolder holder, int position) {
        Student student = studentList.get(position);
        holder.fullNameTextView.setText(student.getFullName());
        // 绑定其他数据
    }

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

    public static class StudentViewHolder extends RecyclerView.ViewHolder {
        TextView fullNameTextView;
        // 其他视图

        public StudentViewHolder(@NonNull View itemView) {
            super(itemView);
            fullNameTextView = itemView.findViewById(R.id.fullNameTextView);
            // 初始化其他视图
        }
    }
}

// 在Activity/Fragment中加载数据
private void loadStudentsOnce() {
    FirebaseFirestore db = FirebaseFirestore.getInstance();
    db.collection("Student")
            .orderBy("fullName")
            .get()
            .addOnSuccessListener(queryDocumentSnapshots -> {
                List<Student> students = new ArrayList<>();
                for (DocumentSnapshot document : queryDocumentSnapshots.getDocuments()) {
                    students.add(document.toObject(Student.class));
                }
                customStudentAdapter.setStudentList(students);
            })
            .addOnFailureListener(e -> {
                Log.e("Firestore", "Error fetching students", e);
            });
}

// 初始化RecyclerView和适配器
// rv.setAdapter(customStudentAdapter);
// loadStudentsOnce(); // 在需要时调用加载方法

public class CustomRealtimeStudentAdapter extends RecyclerView.Adapter<CustomRealtimeStudentAdapter.StudentViewHolder> {

    private List<Student> studentList;
    private FirebaseFirestore db;
    private ListenerRegistration registration; // 用于管理监听器生命周期

    public CustomRealtimeStudentAdapter() {
        this.studentList = new ArrayList<>();
        this.db = FirebaseFirestore.getInstance();
    }

    // 启动监听
    public void startListening(Query baseQuery) {
        registration = baseQuery.addSnapshotListener((snapshots, e) -> {
            if (e != null) {
                Log.w("Firestore", "Listen failed.", e);
                return;
            }

            if (snapshots != null) {
                for (DocumentChange dc : snapshots.getDocumentChanges()) {
                    Student student = dc.getDocument().toObject(Student.class);
                    int oldIndex = dc.getOldIndex();
                    int newIndex = dc.getNewIndex();

                    switch (dc.getType()) {
                        case ADDED:
                            studentList.add(newIndex, student);
                            notifyItemInserted(newIndex);
                            break;
                        case MODIFIED:
                            // 如果顺序可能改变，需要先移除旧位置，再插入新位置
                            // 或者如果只是内容改变，且位置不变，直接notifyItemChanged
                            if (oldIndex == newIndex) {
                                studentList.set(newIndex, student);
                                notifyItemChanged(newIndex);
                            } else {
                                studentList.remove(oldIndex);
                                studentList.add(newIndex, student);
                                notifyItemRemoved(oldIndex);
                                notifyItemInserted(newIndex);
                            }
                            break;
                        case REMOVED:
                            studentList.remove(oldIndex);
                            notifyItemRemoved(oldIndex);
                            break;
                    }
                }
            }
        });
    }

    // 停止监听
    public void stopListening() {
        if (registration != null) {
            registration.remove();
            registration = null;
        }
    }

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

    @Override
    public void onBindViewHolder(@NonNull StudentViewHolder holder, int position) {
        Student student = studentList.get(position);
        holder.fullNameTextView.setText(student.getFullName());
    }

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

    public static class StudentViewHolder extends RecyclerView.ViewHolder {
        TextView fullNameTextView;

        public StudentViewHolder(@NonNull View itemView) {
            super(itemView);
            fullNameTextView = itemView.findViewById(R.id.fullNameTextView);
        }
    }
}

// 在Activity/Fragment中使用
// private CustomRealtimeStudentAdapter myStudentAdapter;
// private Query baseQuery; // 根据搜索和过滤条件构建的Firestore查询

// @Override
// public void onStart() {
//     super.onStart();
//     myStudentAdapter.startListening(baseQuery);
// }

// @Override
// public void onStop() {
//     super.onStop();
//     myStudentAdapter.stopListening();
// }