MVC自定义验证逻辑

1、将验证逻辑封装在自定义数据注解中，优点是可重用，但实现起来需要考虑多个模型对象。

using System.ComponentModel.DataAnnotations;

namespace MvcApplication1.Models
{
    public class CommonValidation:ValidationAttribute
    {
        public override ValidationResult IsValid(object value,ValidationContext validationcontext)
        {
            if (value != null)
            {
                var valueasstring = value.ToString();
                if (valueasstring.Split(' ').Length > _maxwords)
                {
                    var errormessage = FormatErrorMessage(validationcontext.DisplayName);
                    return new ValidationResult(errormessage);
                }
            }
            return ValidationResult.Success;
        }

        private int _maxwords;

        public CommonValidation(int MaxWords):base("{0} has too many wor")
        {
            _maxwords = MaxWords;
        }
    }

}

　　

2、将验证逻辑封装在模型对象中，优点是验证逻辑只需要对一个模型对象负责，但缺点是不能实现多个模型对象的重用。

 

 public class Order:IValidatableObject
    {
        public IEnumerable<ValidationResult> Valide(ValidationContext validationcontext)
        {
            if (LastName != null&&LastName.Split(' ').Length>10)
            {
                yield return new ValidationResult("The Last name has too many words!", new[] { "LastName" });
            }
        }

        public string LastName { get; set; }