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; } } }