Custom Listview with Radio button .I need single selection of radio button from multiple list of radio buttons

Question

I have A custom listview Which contain Radio button and Text View .When i Select 1 Radio button there are multiple radio button selected.Every next 4 index radio button also selected.i want to select only 1 radio button at a time.

This is the adapter code

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();
            }
        }
    }
}

This is the Windowpopup Code

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;
        } 

This is the Xamal For 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>

Layout xamal Which Contain the Radio button and text When the Api Call it return The text and bind with this edit text

  <?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>

This Layout Contain the ListView which show the data

<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>

Answer 1

You placed the radio button on each list view item, they are not associated with each other as they are not in the same RadioGroup. You have to define a property in your model to point out which radio should be checked.

I simulate your model like:

public class DepartmentDto
{
    public string Afdeling_Txt { set; get; }

    public bool Checked { set; get; }
}

And your GetView event should be adjusted:

public override View GetView(int position, View convertView, ViewGroup parent)
{
    var view = convertView ?? activity.LayoutInflater.Inflate(Resource.Layout.DepartmentPopUpListViewRow, parent, false);
    // var DepartmentpopUp = 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.SetOnCheckedChangeListener(this);

    view.FindViewById<TextView>(Resource.Id.SelectDepartmentName).Text = Departments[position].Afdeling_Txt;
    return view;
}
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();
    }
}

Do not forget to implement the IOnCheckedChangeListener interface in your adapter: public class DepartmentListAdapter : BaseAdapter<DepartmentDto>, IOnCheckedChangeListener.

At last, the constructor of adapter could be like this:

List<DepartmentDto> list = new List<DepartmentDto>();
for (int i = 0; i<10; i++)
{
    list.Add(new DepartmentDto { Checked = false, Afdeling_Txt = "item" + i });
}

DepartmentListAdapter customAdapter = new DepartmentListAdapter(this, list);
Departmentlistview.Adapter = customAdapter;

Answer 2

Right now your radio buttons are part of different layouts. Since you are not using Xamarin Forms, the way Android suggest it's usage it to place all the radio buttons in a single radio group, as you can see below.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <RadioGroup
        android:id="@+id/radioGender"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >
        <RadioButton
            android:id="@+id/radioMale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Male" 
            android:checked="true" />
        <RadioButton
            android:id="@+id/radioFemale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Female" />

    </RadioGroup>
    ...Other stuff in the layout...
</LinearLayout>