How to get checked radio button and how to control only one radio button selected in list view

Question

I trying to add my data to a list view. I am using adapter on this. Inside the list view have radio button and some field.

class StocktakeEditViewAdaptor : BaseAdapter<Model.FileRecord>
{
private Dictionary<int, bool> checkDictionary = new Dictionary<int, bool>();



public override View GetView(int position, View convertView, ViewGroup parent)
    {
        var item = items[position];
        View view = convertView;

        //if (view == null)
        {
            view = context.LayoutInflater.Inflate(Resource.Layout.StockTakeEditDetailList, null);
            view.DuplicateParentStateEnabled = true;


            createdview.Add(view);
            RadioButton lblradio = view.FindViewById<RadioButton>(Resource.Id.lblradio);
            lblradio.Tag = item.FileRecord_ID + ":" + item.ST_filename + ":" + item.ST_BinLoc;
lblradio.Checked = checkDictionary[position];   //add position here
            lblradio.SetOnCheckedChangeListener(null);
            lblradio.SetOnCheckedChangeListener(new CheckedChangeListener(this.context));

            view.FindViewById<TextView>(Resource.Id.txtLineNo).Text = item.FileRecord_ID.ToString();  //my field in adapter.
            view.FindViewById<TextView>(Resource.Id.txtbinloc).Text = item.ST_BinLoc.ToString();
            view.FindViewById<TextView>(Resource.Id.txtBarcodett).Text = item.ST_Barcode.ToString();
            view.FindViewById<TextView>(Resource.Id.txtQtytt).Text = item.ST_Qty.ToString();


            if (!view.HasOnClickListeners)
                view.Click += View_LongClick;
            view.RefreshDrawableState();
        }
        return view;
    }

        public void OnCheckedChanged(CompoundButton buttonView, bool isChecked)
        {
            for (int i = 0; i < checkDictionary.Count(); i++)
            {
                if (i == (int)buttonView.Tag)
                {
                    checkDictionary[i] = true;   //error on here
                }
                else
                {
                    checkDictionary[i] = false;  //error on here
                }
            }

        }

I able to show my record in list view.But the radio button can select multiple. I do not want select multiple record.

Answer 1

The reason you can select multiple radio button is that they do not belong to the same Radio button group.

A quote from the official document of Android Radiobutton.

To create each radio button option, create a RadioButton in your layout. However, because radio buttons are mutually exclusive, you must group them together inside a RadioGroup. By grouping them together, the system ensures that only one radio button can be selected at a time.

How to do this?

RadioGroup is just like a view group for Radiobuttons so you can use it just like one

XML:

<?xml version="1.0" encoding="utf-8"?>
<RadioGroup xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RadioButton android:id="@+id/radio_pirates"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/pirates"
    android:onClick="onRadioButtonClicked"/>
<RadioButton android:id="@+id/radio_ninjas"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/ninjas"
    android:onClick="onRadioButtonClicked"/>
</RadioGroup>

C#:

RadioGroup rg = new RadioGroup(this); //create the RadioGroup
rg.Orientation = Orientation.Horizontal;//or Orientation.VERTICAL
RadioButton rb = new RadioButton(this);// create the radiobutton
rg.AddView(rb);// add to radio group 

Answer 2

You could create a collection to store the check status of the radiobutton, and then load the collection when it is loaded in getView. like this :

class YourAdapter : BaseAdapter,CompoundButton.IOnCheckedChangeListener
    {
        private Dictionary<int, bool> checkDictionary = new Dictionary<int, bool>();
        int[] item;  //raplace your own data
        public MyAdapter(int[] value) //raplace your own data
        {
            item = value;
            for (int i = 0; i < item.Length; i++)
            {
                checkDictionary.Add(i,false);
            }
        }



public override View GetView(int position, View convertView, ViewGroup parent)
    {
       var item = items[position];
       View view = convertView;

    //if (view == null)
      {
        view = context.LayoutInflater.Inflate(Resource.Layout.StockTakeEditDetailList, null);
        view.DuplicateParentStateEnabled = true;


        createdview.Add(view);
        RadioButton lblradio = view.FindViewById<RadioButton>(Resource.Id.lblradio);

        lblradio.Tag = position;
        lblradio.Checked = checkDictionary[position];
        lblradio.SetOnCheckedChangeListener(this);

        view.FindViewById<TextView>(Resource.Id.txtLineNo).Text = item.FileRecord_ID.ToString();  //my field in adapter.
        view.FindViewById<TextView>(Resource.Id.txtbinloc).Text = item.ST_BinLoc.ToString();
        view.FindViewById<TextView>(Resource.Id.txtBarcodett).Text = item.ST_Barcode.ToString();
        view.FindViewById<TextView>(Resource.Id.txtQtytt).Text = item.ST_Qty.ToString();


        if (!view.HasOnClickListeners)
            view.Click += View_LongClick;
        view.RefreshDrawableState();
      }
        return view;
    }
public void OnCheckedChanged(CompoundButton buttonView, bool isChecked)
    {
        for (int i = 0; i < checkDictionary.Count; i++)
         {
           if (i == (int) buttonView.Tag)
            {
                checkDictionary[i] = true;
            }
           else
            {
                checkDictionary[i] = false;
            }
         }
            NotifyDataSetChanged();

      }
   }