Example of formatted input for EditText using Xamarin Android

EditTextActivity.cs

using Android.App;
using Android.Widget;
using Android.OS;
using Android.Views;
using Android.Text;
using Android.Runtime;
using Java.Text;
using System.Text.RegularExpressions;

namespace EditTextExample
{
	[Activity (Label = "EditTextExample", MainLauncher = true, Icon = "@mipmap/icon")]
	public class MainActivity : Activity
	{
		private EditText _editText;

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

			// Set our view from the "main" layout resource
			SetContentView (Resource.Layout.Main);

			_editText = FindViewById<EditText> (Resource.Id.myEditField);
			_editText.AfterTextChanged += EditText_AfterTextChanged;
		}

		private void EditText_AfterTextChanged(object sender, AfterTextChangedEventArgs e)
		{
			var text = e.Editable.ToString();
			_editText.AfterTextChanged -= EditText_AfterTextChanged;
			var formatedText = PhoneNumberValueConverter(text);
			_editText.Text = formatedText;
			_editText.SetSelection(formatedText.Length);
			_editText.AfterTextChanged += EditText_AfterTextChanged;
		}

		private static string PhoneNumberValueConverter(string text)
		{
			var numbers = Regex.Replace(text, @"\D", "");

			if (numbers.Length <= 3)
				return numbers;
			if (numbers.Length <= 7)
				return string.Format("{0}-{1}", numbers.Substring(0, 3), numbers.Substring(3));

			return string.Format("({0}) {1}-{2}", numbers.Substring(0, 3), numbers.Substring(3, 3), numbers.Substring(6));
		}
	}



}

Thanks.great example