Question

Is it possible to specify field name using some strongly-typed way (lambda?) in such situation:

public class Demo : IValidatableObject
{
    public string DemoField {get; set;}

    IEnumerable<ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
    {
        if (<...>)
        {
            yield return new ValidationResult("Some validation message", new string[] { "DemoField" }); // <-- Here
        }
    }

}

When field name is specified in string it can’t be refactored, for example.

Answer 1

I am not aware of any “built-in” way. But you could use LINQ expressions to do something like this:

Expression<Func<Demo, string>> lambda = (Demo d) => d.DemoField;
string demoFieldName = ((System.Linq.Expressions.MemberExpression)lambda.Body).Member.Name;
yield return new ValidationResult("Some validation message", new string[] { demoFieldName });

This way you have no hard-coded strings, and refactoring will work.