pass prop as param to another prop custom attribute c#

Question

i want to pass a property as a parameter to another property custom attribute but i can't because its not static Model ex :

public class model1
{
     public DateTime param1 { get; set; }
     [CustomAttribute (param1)]
     public string param2 { get; set; }
}

public class CustomAttribute : ValidationAttribute
{
    private readonly DateTime _Date;
    public CustomAttribute(DateTime date)
    {
        _Date= date;
    }
}

because i want to make a custom validation between this two attributes .

Check this out https://stackoverflow.com/a/7026441/9695286 – Karan Nov 29 '18 at 10:03 — Karan, Nov 29 '18 at 10:03

score 0 · Accepted Answer · answered Nov 29 '18 at 10:47

Attributes are not stored as executable code, so there are significant limitations on the kind of data you can include in them.

Basically, you must stick with base types: strings, numbers, dates. Everything that can be a constant.

Fortunately, you can use a bit of reflection and the nameof operator:

public class model1
{
     public DateTime param1 { get; set; }
     [CustomAttribute (nameof(param1))]
     public string param2 { get; set; }
}

public class CustomAttribute : ValidationAttribute
{
    private readonly string _propertyName;
    public CustomAttribute(string propertyName)
    {
        _propertyName = propertyName;
    }
}

Keep in mind that the validation logic should reside outside the attribute's code.

The needed ingredients for the validation will be Type.GetProperties, PropertyInfo.GetValue, and MemberInfo.GetCustomAttribute.

If you need a complete example and care to better explain the use case, let me know.

Then, if your problem is solved, upvote the answer (with the up arrow) and accept it as the proper answer (selecting the green mark). — Alberto Chiesa, Nov 29 '18 at 11:24

pass prop as param to another prop custom attribute c#

1 Answers1