java .lang.ClassCastException: androidx.constraintlayout.widget.ConstraintLayout нельзя привести к android .widget.TextView

Question

String teacher_id;
String class_selected;
Spinner period;
String periodno;
ArrayList<String> selectedItems;
ArrayList<String> nonselectedItems;
//Toolbar mToolbar;
ArrayList<String> ul;
ListView listView;
private ArrayAdapter adapter;
ArrayList Userlist = new ArrayList<String>();
ArrayList Usernames = new ArrayList<String>();

DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
DatabaseReference dbAttendance;
String date = new SimpleDateFormat("dd-MM-yyyy").format(new Date());

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_takeattendance);
    period = (Spinner) findViewById(R.id.spinner5);

    // ArrayList Userlist;
    selectedItems = new ArrayList<String>();

    TextView classname = (TextView) findViewById(R.id.textView5);
    classname.setText("CSE");

    //to get class name from teacherlogin
    Bundle bundle1 = getIntent().getExtras();
    class_selected = bundle1.getString("class_selected");
    teacher_id = bundle1.getString("tid");
    //  Toast.makeText(getApplicationContext(), teacher_id, Toast.LENGTH_LONG).show();

    classname.setText(class_selected);


    DatabaseReference dbuser = ref.child("Student");

    dbuser.orderByChild("classes").equalTo(class_selected).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            for (DataSnapshot dsp : dataSnapshot.getChildren()) {
                Userlist.add(dsp.child("sid").getValue().toString());
                Usernames.add(dsp.child("sname").getValue().toString());


            }
            OnStart(Userlist);

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Toast.makeText(getApplicationContext(), "something went wrong", Toast.LENGTH_LONG).show();
        }

    });
}
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void OnStart(ArrayList<String> userlists) {
        nonselectedItems = userlists;
        ListView chl = (ListView) findViewById(R.id.checklist);
        chl.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

        ArrayAdapter<String> aa = new ArrayAdapter<String>(this, R.layout.checkable_list_layout, R.id.txt_title, userlists);
        chl.setAdapter(aa);

        chl.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                String selectedItem = ((TextView) view).getText().toString();
                if (selectedItems.contains(selectedItem))
                    selectedItems.remove(selectedItem);
                else
                    selectedItems.add(selectedItem);

            }

        });


    }

    public void showSelectedItems(View view) {
        String selItems = "";
        periodno = period.getSelectedItem().toString();
        if (periodno.equals("Select Period")) {
            Toast.makeText(this, "Select a class", Toast.LENGTH_LONG).show();

        } else {
            ref = FirebaseDatabase.getInstance().getReference();

            dbAttendance = ref.child("attendance").child(date);

            for (String item : selectedItems) {
                Toast.makeText(this, "Attendance created Successfully", Toast.LENGTH_SHORT).show();
                nonselectedItems.remove(item);
                dbAttendance.child(item).child(periodno).setValue("P" + " / " + teacher_id);
                if (selItems == "")
                    selItems = item;
                else
                    selItems += "/" + item;
            }
            // Toast.makeText(this, selItems, Toast.LENGTH_LONG).show();


            //for making absent
            for (String item : nonselectedItems) {
                Toast.makeText(this, "Attendance created Successfully", Toast.LENGTH_SHORT).show();
                dbAttendance.child(item).child(periodno).setValue("A" + " / " + teacher_id);
                //Toast.makeText(this, "absentees:" + nonselectedItems, Toast.LENGTH_LONG).show();

            }
        }


    }



    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }


}

logcat 2020-05-03 18: 14: 36.533 15945-15945 / com.samarthjain.attendancemanager E / AndroidRuntime: FATAL EXCEPTION: main Процесс: com.samarthjain.attendancemanager, PID: 15945 java .lang.ClassCastException: androidx.constraintlayout.widget.ConstraintLayout не может быть приведен к android .widget.TextView в com.samarthjain.attendancemanager.takeattendance $ 2.onItemClick (takeattendance. java: 106) в android. .AdapterView.performItemClick (AdapterView. java: 330) в android .widget.AbsListView.performItemClick (AbsListView. java: 1213) в android .widget.AbsListView $ PerformClick.run (AbsListView. java). : 3221) в android .os.Handler.handleCallback (Обработчик. java: 883) в android .os.Handler.dispatchMessage (Обработчик. java: 100) в android .os.Looper. l oop (Looper. java: 214) в android .app.ActivityThread.main (ActivityThread. java: 7403) в java .lang.reflect.Method.invoke (собственный метод) в com . android .internal.os.RuntimeInit $ MethodAndArgsCaller.run (RuntimeInit. java: 492) в com. android .interna l.os.ZygoteInit.main (. ZygoteInit java: 935) `