🚀 go-pugleaf

I am trying to make a DLL to use ADO I created some functions in this DLL,
am having problems in two of them the first one that it returns the Fields
(TFields *) and another one the Field (TField *), but when I arrive at the
end of one for it gives to an error invalid to pointer operation.
Some idea?

Code:
First Form -->

void fnGetFields(TObject* objData,TFields& Fields)
{
   try {
      Fields = ((TADODataSet*)objData)->Fields;
   } catch (...) {
   }
}

void fnGetField(TObject* objData,char* cField,TField& Field)
{
   try {
      Field = ((TADODataSet*)objData)->FieldByName(cField);
   } catch (...) {
   }
}

For:
// tb is Private Object
// ls is ListBox
TFields    fFields;
TField     fField;
String     strData,strName;
fnGetFields(tb,fFields);
for (int i = 0;i < fFields->Count;i++) {
    strName = fFields->Fields[i]->DisplayName;
    fnGetField(tb,strName.c_str(),fField);
    strData = fField->AsString;
   ls->Lines->Add(strName + " " + strData);
} // Error: Invalid pointer operation

Second Form -->

TFields* fnGetFields(TObject* objData)
{
   TFields* fFields;
   try {
      fFields = ((TADODataSet*)objData)->Fields;
   } catch (...) {
   }
   return(fFields);
}

TField* fnGetField(TObject* objData,char* cField)
{
   TField* fField;
   try {
      fField = ((TADODataSet*)objData)->FieldByName(cField);
   } catch (...) {
   }
   return(fField);
}

For:
// tb is Private Object
// ls is ListBox
TFields    fFields;
TField     fField;
String     strData,strName;
fFields = fnGetFields(tb);
for (int i = 0;i < fFields->Count;i++) {
    strName = fFields->Fields[i]->DisplayName;
    fField = fnGetField(tb,strName.c_str());
    strData = fField->AsString;
   ls->Lines->Add(strName + " " + strData);
} // Error: Invalid pointer operation