using System;

using System.ComponentModel.DataAnnotations;

using System.Collections.Generic;

public class Program

{

    public class LoginModel

{

    [MaxLength(2)]

    public string UserName { get; set; }

​

    [MaxLength(10)]

    public string Password { get; set; }

}

    public class FieldLength

    {

        public string Name{get;set;}

        public int Value{get;set;}

    }

    public static List<FieldLength> GenerateValidationModel<T>()

{

    List<FieldLength> FieldVal= new List<FieldLength>();

    foreach (var prop in typeof(T).GetProperties())

    {

        object[] attrs = prop.GetCustomAttributes(true);

        if (attrs == null || attrs.Length == 0)

            continue;

​

        int conds =0;

​

        foreach (Attribute attr in attrs)

        {

            if (attr is MaxLengthAttribute)

            {

                conds +=  (attr as MaxLengthAttribute).Length;

            }          

        }

​

        if (conds > 0)

            FieldVal.Add(new FieldLength() { Name = prop.Name, Value = conds });

    }

    return FieldVal;

}

    public static void Main()

    {

        var FieldVal = GenerateValidationModel<LoginModel>();

    foreach(var item in FieldVal)

        {

            Console.WriteLine(item.Name + "  "+item.Value );

        }

        //Console.WriteLine(FieldVal.Name);

    }

}