c# - MVC3 自定义验证

Question

我有一个有属性的模型

    [Display(Name = "Phone")]
    public List<Phone> PhoneNumbers { get; set; }

我想验证 List 应该大于 0

建议我的代码。

/// <summary>
/// Atleast one phone number is required
/// </summary>
public sealed class DemographicPhoneNumberRequiredCheck : ValidationAttribute
{
    public override bool IsValid(object value)
    {
       ???????
    }
}

谢谢。

Answer 1

您可以使用Count或Any：

   public override bool IsValid(object value)
    {
       var PhoneNumbers = value as List<Phone>;
       if (PhoneNumbers != null) 
       {
          return PhoneNumbers.Count() > 0;
       }

       return false;
    }

或者：

    public override bool IsValid(object value)
    {
       var PhoneNumbers = value as List<Phone>;
       if (PhoneNumbers != null) 
       {
          return PhoneNumbers.Any();
       }
    }

Answer 2

实际上，您的方法具有价值：

public override bool IsValid(object value)
{
    var phoneNumbers = value as List<Phone>;
    if(phoneNumbers != null) 
    {
        // perform the validation
    }
}