如何过滤具有从Firebase数据库检索的值列表的ListView

Question

我已经在ListView中从Firebase数据库检索数据。它具有两个Textviews 1）学生姓名2）学生班级。现在，我想用Edit_Text过滤此ListView，也要用ListView过滤onClickListener，但是我无法做到这一点。当我在Edit_Text中键入内容时，整个列表为空。这是我的代码

StudentsInfoAdapter.java

public class StudentsInfoAdapter extends ArrayAdapter<Students> {

    private Activity context;
    private List<Students> studentsList;

    public StudentsInfoAdapter(Activity context,List<Students>studentsList){
        super(context,R.layout.list_view,studentsList);
        this.context=context;
        this.studentsList=studentsList;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        LayoutInflater inflater = context.getLayoutInflater();
        View listView = inflater.inflate(R.layout.list_view,null,true);

        TextView studentName = listView.findViewById(R.id.name);
        TextView studentClass = listView.findViewById(R.id.class_of_student);

        Students student = studentsList.get(position);
        studentName.setText(student.getStudentName());
        studentClass.setText(student.getStudentClass());

        return listView;
    }

    
}

activity_data_retrieved.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".DataRetrieved">
    <EditText
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:hint="Search"
        android:id="@+id/inputSearch"/>

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:dividerHeight="10dp"
        android:divider="@android:color/transparent"
        android:id="@+id/list_view"/>

</LinearLayout>

DataRetrieved.java

public class DataRetrieved extends AppCompatActivity {

    private ListView listView;
    DatabaseReference databaseReference;
    List<Students> studentsList;
    public EditText inputSearch;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        inputSearch = findViewById(R.id.inputSearch);
        setContentView(R.layout.activity_data_retrieved);
        listView=findViewById(R.id.list_view);
        databaseReference = FirebaseDatabase.getInstance().getReference("students");
        studentsList = new ArrayList<>();
    }



    @Override
    protected void onStart() {
        super.onStart();
        inputSearch = findViewById(R.id.inputSearch);
        databaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    for (DataSnapshot studentSnapshot : dataSnapshot.getChildren()){
                        Students student = studentSnapshot.getValue(Students.class);
                        studentsList.add(student);
                    }
                    final StudentsInfoAdapter studentsInfoAdapter = new StudentsInfoAdapter(DataRetrieved.this,studentsList);
                    listView.setAdapter(studentsInfoAdapter);
                    inputSearch.addTextChangedListener(new TextWatcher() {
                        @Override
                        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                            
                        }

                        @Override
                        public void onTextChanged(CharSequence s, int start, int before, int count) {
                            studentsInfoAdapter.getFilter().filter(s);
                        }

                        @Override
                        public void afterTextChanged(Editable s) {

                        }
                    });



            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }

}

Answer 1

        List<Students> studentsList = new ArrayList<>();
        List<Students > studentsListSearch = new ArrayList<>();// add this line

      public StudentsInfoAdapter(Activity context,List<Students>studentsList){
             super(context,R.layout.list_view,studentsList);
             this.context=context;
            this.studentsList=studentsList;
            studentsListSearch.addAll(studentsList);//add this line
       }


                   @Override
                    public void onTextChanged(CharSequence s, int start, int before, int count) {

                if(s.toString().length()>0){
                        studentsList.clear();

                       String searchTxt = holder.tvExpLstAdptrSlNo.getText().toString();

                   for(String s: studentsListSearch){
                      if(s.toLowerCase().contains(searchTxt)){
                           studentsList.add(s);
                       }
                     }
                      studentsInfoAdapter.notifyChanged();
                 }
                 else{
                     studentsList.addAll(studentsListSearch);
                    studentsInfoAdapter.notifyChanged();
                 }

              }