c# conditional Required Attribute

Question

how can i to put conditional Required Attribute into class? i tried the following code and it doesn't work.

public partial class Zone
{
    [RequireCondition ]
    public int LastCount { get; set; }
}
public class RequireCondition : ValidationAttribute
    {
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            var Zone = (Zone)validationContext.ObjectInstance;
            if (Zone.LastCount < 1)
            {
                return new ValidationResult("Last Count value must be greater than one.");
            }
            else
           {
                return ValidationResult.Success;
           }
        }
    }

What does "it doesn't work" mean? What did you find when you debugged it? — ProgrammingLlama, Nov 20 '17 at 02:58
the condition cant be work, i still can proceed whenever the value is less than 1 — user3835327, Nov 20 '17 at 03:01
[Downvote reason](http://idownvotedbecau.se/itsnotworking/) - please read, it's educational. You can find out the value of `value` by placing a breakpoint on the line starting `var Zone =` and inspecting the value of `value`. — ProgrammingLlama, Nov 20 '17 at 03:02

zaitsman · Accepted Answer · 2017-11-20T03:08:34.873

Try this?

public partial class Zone
{
    [RequireCondition(1)]
    public int LastCount { get; set; }
}

public class RequireConditionAttribute : ValidationAttribute
 {
     private int _comparisonValue;

     public RequireCondition(int comparisonValue)
     {
        _comparisonValue = comparisonValue;
     }

     protected override ValidationResult IsValid(object value, ValidationContext validationContext)
      {              
        if (value is int && (int)value < comparisonValue)
            {
              return new ValidationResult($"{validationContext.DisplayName} value must be greater than one.");
            }

            return ValidationResult.Success;
        }
    }

hi, there's an error, operator '<' cannot be applied to operands of type 'object' and 'int' .. in line of (value > comparisonvalue) — user3835327, Nov 20 '17 at 03:07

c# conditional Required Attribute

1 Answers1