Flatten PDF form

// open 'U.S. Individual Income Tax Return' form
using (FileStream fileIn = new FileStream("f1040a.pdf", FileMode.Open, FileAccess.Read))
{
   Document form = new Document(fileIn);

   // activate the javascript engine, so format actions will be executed.
   form.ScriptBehavior = ScriptBehavior.Format;

   // flatten all form-data with the current value, except text-field field-name.
   foreach(Field field in form.Fields)
   {
      TextField textField = field as TextField;
      if (textField != null)
      {
         textField.Value = textField.FullName;
      }

      foreach( Widget widget in field.Widgets )
      {
         widget.Persistency = WidgetPersistency.Flatten;
      }
   }

   // write flattened form back to disk
   using (FileStream fileOut = new FileStream("flattenform.pdf", FileMode.Create, FileAccess.Write))
   {
      form.Write(fileOut);
   }
}

// open 'U.S. Individual Income Tax Return' form
Using fileIn As New FileStream("..\..\..\inputDocuments\f1040a.pdf", FileMode.Open, FileAccess.Read)
            Dim form As New Document(fileIn)

            'Activate the javascript engine, so format actions will be executed.
            form.ScriptBehavior = ScriptBehavior.Format

            'Flatten all form-data with the current value, except text-field field-name.
            For Each field As Field In form.Fields
                Dim textField As TextField = TryCast(field, TextField)
                If textField IsNot Nothing Then
                    textField.Value = textField.FullName
                End If

                For Each widget As Widget In field.Widgets
                    widget.Persistency = WidgetPersistency.Flatten
                Next
            Next

            ' write flattened form back to disk
            Using fileOut As New FileStream("..\..\flattenform.pdf", FileMode.Create, FileAccess.Write)
                form.Write(fileOut)
            End Using
        End Using