Xamarin Android SMS Send Test

MainActivity.cs

using Android.App;
using Android.Widget;
using Android.OS;
using Android.Content;
using Android.Telephony;
using Android.Net;

namespace SmsTest.Android
{
    [Activity(MainLauncher = true, Icon = "@mipmap/icon")]
    public class MainActivity : Activity
    {
        const string telephoneNumber = "-------"; // TODO put telephone number here

        EditText _editText;

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            SetContentView(Resource.Layout.main);

            _editText = FindViewById<EditText>(Resource.Id.editText);

            FindViewById<Button>(Resource.Id.button_inapp).Click += Button_InApp_Click;
            FindViewById<Button>(Resource.Id.button_intent).Click += Button_Intent_Click;
        }

        void Button_InApp_Click(object sender, System.EventArgs e)
        {
            // test sending directly from app
            for (int i = 1; i < 3; i++)
            {
                SmsManager.Default.SendTextMessage(telephoneNumber, null, $"{i}. {_editText.Text}", null, null);
            }
        }

        void Button_Intent_Click(object sender, System.EventArgs e)
        {
            // test putting text message into SMS app
            var smsUri = Uri.Parse($"smsto:{telephoneNumber}");
            var smsIntent = new Intent(Intent.ActionSendto, smsUri);
            smsIntent.PutExtra("sms_body", _editText.Text);
            StartActivity(smsIntent);
        }
    }
}