Пользовательский список с радиокнопкой. Мне нужен один выбор радиокнопки из нескольких списков радиокнопок

У меня есть настраиваемый список, который содержит радиокнопку и текстовое представление. Когда я выбираю 1 радиокнопку, выбирается несколько радиокнопок. Каждые следующие 4 индексных радиокнопки также выбираются. Я хочу выбрать только 1 радиокнопку за раз.

это код адаптера

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Definition.Dto;
using static Android.Widget.CompoundButton;

namespace SGDDPortal.Android.Model
{
    public class ViewHolder : Java.Lang.Object
    {
        public TextView LabelText { get; set; }
        public RadioButton ListRadioButton { get; set; }
    }

    public class DepartmentListAdapter : BaseAdapter<DepartmentDto>, IOnCheckedChangeListener
    {
        private Activity activity;
        List<DepartmentDto> Departments;
        int selectedIndex = -1;

        public DepartmentListAdapter(Activity activity, List<DepartmentDto> Departments)
        {
            this.activity = activity;
            this.Departments = Departments;
        }

        public override DepartmentDto this[int position] => Departments[position];

        public override int Count => Departments.Count;

        public override long GetItemId(int position)
        {
            return position;
        }

        public override View GetView(int position, View convertView, ViewGroup parent)
        {
            var view = convertView ?? activity.LayoutInflater.Inflate(Resource.Layout.DepartmentPopUpListViewRow, parent, false);
            var btnRadio = view.FindViewById<RadioButton>(Resource.Id.SelectedDepartment);
            btnRadio.SetOnCheckedChangeListener(null);
            btnRadio.Tag = position;
            btnRadio.Checked = Departments[position].Checked;
            btnRadio.Text = Departments[position].Afdeling_Txt;
            btnRadio.SetOnCheckedChangeListener(this);


            return view;
        }

        private void BtnRadio_CheckedChange(object sender, CompoundButton.CheckedChangeEventArgs e)
        {
            throw new NotImplementedException();
        }

        public void OnCheckedChanged(CompoundButton buttonView, bool isChecked)
        {
            int position = (int)buttonView.Tag;
            if (isChecked)
            {
                foreach (DepartmentDto model in Departments)
                {
                    if (model != Departments[position])
                    {
                        model.Checked = false;
                    }
                    else
                    {
                        model.Checked = true;
                    }
                }
                NotifyDataSetChanged();
            }
        }
    }
}

Это код Windowpopup

private void DepartmentPicker_Click(object sender, EventArgs e)
        {
            //ViewModelInstances.DepartmentVieModel.PopUpCommand.CanExecute(this);
            ButtonNext.Visibility = ViewStates.Invisible;
            GetListView.ChoiceMode=ListView.ChoiceModeSingle;
            GetListView.Adapter = new DepartmentListAdapter(this, Departments);

            bool focusable = true;
            int width = 350;//LinearLayout.LayoutParams.WrapContent;
            int height = 450;//LinearLayout.LayoutParams.WrapContent;
                             // listView = _PopUpView.FindViewById<ListView>(Resource.Id.Departmentlistview);
            PopupWindow popupWindow = new PopupWindow(_PopUpView, width, height, focusable);
            popupWindow.ContentView = _PopUpView;
            popupWindow.ShowAtLocation(_PopUpView, GravityFlags.CenterVertical, 0, 0);
            popupWindow.Focusable = false;
            popupWindow.Touchable = true;
        } 

Это Xamal для WindowPopUp

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
    android:orientation = "vertical"
    android:layout_width = "match_parent"
    android:gravity = "center"
    android:descendantFocusability = "blocksDescendants"  
    android:layout_height = "wrap_content"
    android:background = "@android:color/background_light"
    android:weightSum = "100">
<LinearLayout
     android:orientation = "horizontal"
     android:layout_width = "match_parent"
        android:layout_weight = "10"
     android:layout_height = "40dp">
    <TextView
        android:text = "Vælg din afdeling"
        android:textSize = "20sp"
        android:textColor = "#FF222222"
        android:paddingLeft = "30dp"
        android:focusable = "false"
        android:focusableInTouchMode = "false"
        android:layout_gravity = "center"
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:minWidth = "25px"
        android:minHeight = "25px"
        android:id = "@+id/textView1" />

        </LinearLayout>
    <LinearLayout
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:layout_weight = "10">
        </LinearLayout>
    <LinearLayout
        android:layout_width = "match_parent"
        android:layout_height = "100dp"
        android:layout_weight = "50">
        <ListView
        android:minWidth = "25px"
        android:minHeight = "25px"
         android:choiceMode = "multipleChoice"
        android:focusable = "false"
        android:layout_width = "match_parent"
        android:layout_height = "match_parent"
        android:id = "@+id/Departmentlistview" />
       </LinearLayout>
     <LinearLayout
    android:layout_width = "fill_parent"
    android:layout_height = "wrap_content"
    android:orientation = "horizontal"
    android:layout_marginTop = "35dp">
    <View
        android:layout_width = "0dp"
        android:layout_height = "0dp"
        android:layout_weight = "1"/>

    <Button
        android:id = "@+id/btnAddExpense"
        android:layout_width = "wrap_content"
        android:layout_height = "45dp"
        android:textColor = "#61222222"
        android:background = "@null"
        android:text = "Annuller"
        android:layout_marginLeft = "20dp"
        android:layout_gravity = "right"
        android:layout_marginRight = "15dp" />
    <Button
        android:id = "@+id/btnok"
        android:layout_width = "wrap_content"
        android:layout_height = "45dp"
        android:textColor = "#FFF62F5E"
        android:text = "Gem"
        android:background = "@null"
        android:layout_marginLeft = "1dp" 
        android:layout_gravity = "right"
        android:layout_marginRight = "15dp" />

</LinearLayout>

</LinearLayout>

Макет xamal, который содержит переключатель и текст, когда API вызывает его, возвращает текст и связывает с этим текстом редактирования

  <?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
    android:orientation = "horizontal"
    android:layout_width = "match_parent"
    android:layout_height = "match_parent"
     android:background = "@android:color/background_light" 
    android:weightSum = "100">
      <RadioGroup
        android:id = "@+id/radioGender"
        android:layout_width = "wrap_content"
        android:layout_height = "wrap_content" >
    <RadioButton    
            android:layout_width = "wrap_content"
            android:layout_height = "60dp"
            android:checked = "false"
            android:id = "@+id/SelectedDepartment" /> 

    </RadioGroup>
        <TextView
            android:text = "303 - Lorem ipsum"
            android:layout_weight = "50"
            android:layout_marginTop = "20dp"
            android:textColor = "#FF222222"
            android:layout_width = "wrap_content"
            android:layout_height = "60dp"
            android:id = "@+id/SelectDepartmentName" />
</LinearLayout>

Этот макет содержит ListView, который показывает данные

<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
    android:orientation = "vertical"
    android:layout_width = "match_parent"
    android:gravity = "center"
    android:descendantFocusability = "blocksDescendants"  
    android:layout_height = "wrap_content"
    android:background = "@android:color/background_light"
    android:weightSum = "100">
<LinearLayout
     android:orientation = "horizontal"
     android:layout_width = "match_parent"
        android:layout_weight = "10"
     android:layout_height = "40dp">
    <TextView
        android:text = "Vælg din afdeling"
        android:textSize = "20sp"
        android:textColor = "#FF222222"
        android:paddingLeft = "30dp"
        android:focusable = "false"
         android:focusableInTouchMode = "false"
        android:layout_gravity = "center"
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:minWidth = "25px"
        android:minHeight = "25px"
        android:id = "@+id/textView1" />

        </LinearLayout>
    <LinearLayout
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:layout_weight = "10">
        </LinearLayout>
    <LinearLayout
        android:layout_width = "match_parent"
        android:layout_height = "100dp"
        android:layout_weight = "50">
        <ListView
        android:minWidth = "25px"
        android:minHeight = "25px"
         android:choiceMode = "singleChoice"
        android:focusable = "false"
        android:layout_width = "match_parent"
        android:layout_height = "match_parent"
        android:id = "@+id/Departmentlistview" />
       </LinearLayout>
     <LinearLayout
    android:layout_width = "fill_parent"
    android:layout_height = "wrap_content"
    android:orientation = "horizontal"
    android:layout_marginTop = "35dp">
    <View
        android:layout_width = "0dp"
        android:layout_height = "0dp"
        android:layout_weight = "1"/>

    <Button
        android:id = "@+id/btnAddExpense"
        android:layout_width = "wrap_content"
        android:layout_height = "45dp"
        android:textColor = "#61222222"
        android:background = "@null"
        android:text = "Annuller"
        android:layout_marginLeft = "20dp"
        android:layout_gravity = "right"
        android:layout_marginRight = "15dp" />


    <Button
        android:id = "@+id/btnok"
        android:layout_width = "wrap_content"
        android:layout_height = "45dp"
        android:textColor = "#FFF62F5E"
        android:text = "Gem"
        android:background = "@null"
        android:layout_marginLeft = "1dp" 
        android:layout_gravity = "right"
        android:layout_marginRight = "15dp" />

</LinearLayout>

</LinearLayout>