How to determine if a check box is checked?

Q: Can you tell me how to determine if a check box is checked using
FieldFind for FDFDoc and PDFDoc?
FieldFind("FieldName").Current().GetValue().GetStr() generates a
PDFNet exception on this object.

Because the value of the checkbox field is a name you need to use
GetName() instead of GetStr().

So instead of FieldFind("FieldName").Current().GetValue().GetStr()

FieldIterator itr = doc.FieldFind("FieldName");
if (itr != doc.FieldEnd()) {
  Field field = itr.Current();
  if (field.GetType() == Field.Type.e_check)
     string checkbox_state = field.GetValue().GetName();
     // 'Off' means that the checkbox is not checked,
     // The recommended (but not required) name for the on state is