The Nullable object error message should be set to

Question

I have a null error for my runtime DTO object:

I did not understand, because the column is NULL:

[DataContract] public class SearchParametersCompanyDTO { public SearchParametersCompanyDTO(); [DataMember] public CompanyColumnsEnumDTO? Column { get; set; } [DataMember] public int PageIndex { get; set; } [DataMember] public int PageSize { get; set; } [DataMember] public string Term { get; set; } } [DataContract] public enum CompanyColumnsEnumDTO { [EnumMember] CompanyName = 0, [EnumMember] City = 1, [EnumMember] PostCode = 2, } 

This should be a conversion problem, because null is accepted in the column:

  var dto = new SearchParametersCompanyDTO { PageIndex = pageIndex, PageSize = defaultPageSize, Term = term, Column = null }; 

Any idea?

Answer 1

You are trying to apply a null value to an enumeration type (and not a null enumeration type). I assume that you really want to change your cast to:

 Column = (CompanyColumnsEnumDTO?) column 

Answer 2

The problem is that you selected the column value to a non-zero value, CompanyColumnsEnumDTO . Based on this exception, it looks like column is null here, and casting to a non-zero exception throws an exception. Did you mean to drop on CompanyColumnsEnumDTO? instead of this?

Answer 3

Do you need to send to (CompanyColumnsEnumDTO?) Instead of (CompanyColumnsEnumDTO)