ASP.NET-MVC-Study/BlazorApp/BlazorServerApp/Data/WeatherForecast.cs

using System.ComponentModel.DataAnnotations;

namespace BlazorServerApp.Data
{
    public class WeatherForecast
    {
        public DateTime Date { get; set; }

        [Required(ErrorMessage = "Need TemperatureC")]
        [Range(typeof(int), "-100", "100")]
        public int TemperatureC { get; set; }

        public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);

        [Required(ErrorMessage = "Need Summary")]
        [StringLength(10, MinimumLength = 2, ErrorMessage = "2~10")]
        public string? Summary { get; set; }
    }
}