c# Reflection return "Nullable`1"

Question

I define my class, my fields pog_02integer and pog_03smallint are integer that can have null value (int?)

public class v_cCfgDeclaraciones {
  public string pog_idcotizacion {get;set;}
  public string pog_01varchar  {get;set;}
  public int? pog_02integer  {get;set;}
  public int? pog_03smallint  {get;set;}
  public DateTime? pog_04date  {get;set;}
}

How I can return "integer" and not System.DBNull? I try this, but I can't find a way to return "integer" I just returned System.DBNull if I remove "?" in the name of the field as a whole recognizes but can't assign a null value. I would like to help me resolve this problem, where I can define the field with "?" and I recognize the integer data type and not System.DBNull

foreach (System.Data.DataRow dr in dt.Rows){
   object o = Activator.CreateInstance(iSingleType);
   foreach (System.Reflection.PropertyInfo Registro in proRegistro){
     if ((Registro.PropertyType.Namespace != "System.Collections.Generic") && (AtributoLectura(Registro.GetCustomAttributes(true)))){
        TipoDato = Registro.PropertyType.Name;
        if (TipoDato == "Nullable`1") {
            string v = dr[Registro.Name.ToUpper()].GetType().FullName;
            int i = v.IndexOf('.');
            int l = v.Length - i;
            TipoDato = v.Substring(i, l);
        }
        switch (TipoDato){
           case "Char":
           case "String":
              break;
           case "int": case "integer"

Answer 1

There is a helper method to get a nullable type's underlying value type: Nullable.GetUnderlyingType. It will return null if the given type is not a closed over nullable type. I would do something like this:

Type type = Nullable.GetUnderlyingType(Registro.PropertyType) ?? Registro.PropertyType;
string typeName = type.Name;