此问题已在此处找到答案：

firebase android列表视图未显示（1个答案）
firebase实时数据库：未填充回收器视图（1个答案）
17分钟前关门。
我正在尝试从firestore集合中获取学生数据，然后将其显示在回收器视图我的firestore集合和文档中：集合名称是学校代码，文档包含学生信息
模范班：（学生模范班）

package com.example.firestooredemo;

import android.util.Log;

import java.sql.Timestamp;
import java.util.HashMap;

public class Student_Data_Model {
    private String Form_name,StudentName,Subject;
    private Timestamp Ts;
    private long School_ID,Std;
    private HashMap<String, String> QnA;

    private Student_Data_Model(){}

    private Student_Data_Model(long Std,String Form_name,String StudentName,String Subject,Timestamp Ts,long School_ID,HashMap<String, String> QnA){
        this.Std=Std;
        this.Form_name=Form_name;
        this.QnA=QnA;
        this.StudentName=StudentName;
        this.Subject=Subject;
        this.Ts=Ts;
        this.School_ID=School_ID;
    }
    public String getStd() {
        Log.d("ValueCheck", "Standard : "+Std);
        return String.valueOf(Std);
    }

    public void setStd(long std) {
        Std = std;
    }

    public String getForm_name() {
        Log.d("ValueCheck", "FormNAme : "+Form_name);
        return Form_name;
    }

    public void setForm_name(String form_name) {
        Form_name = form_name;
    }

    public String getStudentName() {
        Log.d("ValueCheck", "StudentNAme : "+StudentName);
        return StudentName;
    }

    public void setStudentName(String studentName) {
        StudentName = studentName;
    }

    public String getSubject() {
        Log.d("ValueCheck", "Subject : "+Subject);
        return Subject;
    }

    public void setSubject(String subject) {
        Subject = subject;
    }

    public String getTs() {
        return Ts.toString();
    }

    public void setTs(Timestamp ts) {
        Ts = ts;
    }

    public String getSchool_ID() {
        Log.d("ValueCheck", "SchoolID : "+School_ID);
        return String.valueOf(School_ID);
    }

    public void setSchool_ID(long school_ID) {
        School_ID = school_ID;
    }

    public HashMap<String, String> getQnA() {
        return QnA;
    }

    public void setQnA(HashMap<String, String> qnA) {
        QnA = qnA;
    }
}

activity.java：

package com.example.firestooredemo;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;

import com.firebase.ui.firestore.FirestoreRecyclerAdapter;
import com.firebase.ui.firestore.FirestoreRecyclerOptions;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.Query;
import com.google.firebase.firestore.QueryDocumentSnapshot;
import com.google.firebase.firestore.QuerySnapshot;

import java.util.List;

public class DisplayRecord extends AppCompatActivity {
    TextView Record_Title,DemoD;
    private FirebaseFirestore Fs;
    private RecyclerView FSList;
    private FirestoreRecyclerAdapter<Student_Data_Model,Student_View_Holder> F_Adapter;
    String S_ID,Student;
    List<sdm> stud;
    int S_id;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_display_record);
        FSList=(RecyclerView) findViewById(R.id.RCView);
        FSList.setHasFixedSize(true);
        FSList.setLayoutManager(new LinearLayoutManager(this));
        Intent intent = getIntent();
        Fs=FirebaseFirestore.getInstance();
        Record_Title= (TextView) findViewById(R.id.RecordTitle);
        S_ID = intent.getStringExtra("School ID");
        Record_Title.setText("Records of "+S_ID);
        Log.d("Datacheck","School :"+S_ID);
        S_id=Integer.parseInt(S_ID);
        String TAG="Datacheck";

        Fs.collection("EM_DEMO").document("10th_STD").collection(S_ID)
                .whereEqualTo("Form Name","Tourism, Transport and Communication3")
                .get()
                .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                    @Override
                    public void onComplete(@NonNull Task<QuerySnapshot> task) {
                        if (task.isSuccessful()) {
                            for (QueryDocumentSnapshot document : task.getResult()) {
                                Log.d(TAG, document.getId() + " => " + document.getData().toString());
                                Student=Student+document.getLong("Class")+"\n"+document.get("Subject")+"\n"+document.get("Form Name")+"\n-----\n";
//                                stud.add(document.toObject(s1));
                                Log.d("IMOP",Student);
                            }
                        } else {
                            Log.d(TAG, "Error getting documents: ", task.getException());
                        }
                    }
                });
        //Query Part
        Query Q=Fs.collection("EM_DEMO").document("10th_STD").collection(S_ID).whereEqualTo("Form Name","Tourism, Transport and Communication3");

        // Recycler view Display
        FirestoreRecyclerOptions<Student_Data_Model> Opt=new FirestoreRecyclerOptions.Builder<Student_Data_Model>()
                .setQuery(Q,Student_Data_Model.class)
                .build();

        F_Adapter = new FirestoreRecyclerAdapter<Student_Data_Model, Student_View_Holder>(Opt) {
            @NonNull
            @Override
            public Student_View_Holder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View V= LayoutInflater.from(parent.getContext()).inflate(R.layout.student_data,parent,false);
                return new Student_View_Holder(V);
            }

            @Override
            protected void onBindViewHolder(@NonNull Student_View_Holder holder, int position, @NonNull Student_Data_Model model) {
                holder.StudentName.setText(model.getStudentName());
                holder.Standard.setText(model.getStd());
                holder.SchoolID.setText(model.getSchool_ID()+"");
                holder.Subject.setText(model.getSubject());
                holder.FormName.setText(model.getForm_name());
//                holder.Time.setText(model.getTs()+"");
            }
        };

        FSList.setAdapter(F_Adapter);

        //View Holder
    }

    private class Student_View_Holder extends RecyclerView.ViewHolder {
        private TextView StudentName,Standard,Subject,SchoolID,FormName,Time;
        public Student_View_Holder(@NonNull View itemView) {
            super(itemView);
            StudentName = itemView.findViewById(R.id.StudentName);
            Standard = itemView.findViewById(R.id.Std);
            Subject = itemView.findViewById(R.id.Sub);
            SchoolID = itemView.findViewById(R.id.SchoolID);
            FormName = itemView.findViewById(R.id.FormName);
            Time = itemView.findViewById(R.id.Timestamp);
        }
    }

    @Override
    protected void onStart() {
        super.onStart();
        F_Adapter.startListening();
    }

    @Override
    protected void onStop() {
        super.onStop();
        if(F_Adapter!= null){
            F_Adapter.stopListening();
        }
    }
}

学生资料设计：xml设计截图
但应用内回收器视图仅显示获取的主题值，
应用程序输出
我在student data model类中放置了一些日志消息，以检查是否正在提取数据。但这些日志甚至没有显示日志消息：
带标记的日志：datacheck
带有标记的日志：imop
请帮忙做这个，
提前谢谢。