inabox/InABox.Mobile/InABox.Mobile.Shared/Converters/FormatConverter.cs

using System;
using System.Globalization;
using Xamarin.Forms;

namespace InABox.Mobile
{
    public class FormatConverter : IValueConverter
    {
        public String Format { get; set; }

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var fmt = String.IsNullOrWhiteSpace(Format)
                ? "{0}"
                : $"{{0:{Format}}}";
            
            return String.Format($"{fmt}", value);
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}