ant-design-blazor/components/core/Helpers/Formatter.cs

using System;
using System.Linq.Expressions;

namespace AntDesign.Helpers
{
    internal static class Formatter<T>
    {
        private static readonly Lazy<Func<T, string, string>> _formatFunc = new Lazy<Func<T, string, string>>(GetFormatLambda, true);

        public static string Format(T source, string format)
        {
            return _formatFunc.Value.Invoke(source, format);
        }

        private static Func<T, string, string> GetFormatLambda()
        {
            var type = typeof(T);
            var p1 = Expression.Parameter(typeof(T));
            var p2 = Expression.Parameter(typeof(string));

            Expression body = p2;
            if (type.IsSubclassOf(typeof(IFormattable)))
            {
                var method = type.GetMethod("ToString", new[] { typeof(string), typeof(IFormatProvider) });
                body = Expression.Call(Expression.Convert(p1, type), method, p2, Expression.Constant(null));
            }
            else
            {
                var method = type.GetMethod("ToString", new[] { typeof(string) });
                if (method != null)
                {
                    body = Expression.Call(Expression.Convert(p1, type), method, p2);
                }
            }
            return Expression.Lambda<Func<T, string, string>>(body, p1, p2).Compile();
        }
    }
}