By default, each control appears in its own row. You can change this behavior by using either the siUIContinue item attribute or the PPGLayout or PPGLayout Row methods:
If you set the siUIContinue item attribute to true on a control, the next control appears on the same row. You can use this attribute in this way on several controls consecutively to arrange them all on the same row.
The PPGLayout.AddRow or PPGLayout::AddRow and PPGLayout.EndRow or PPGLayout::EndRow methods are a convenience that allows you to specify where the row should start and end instead of setting the siUIContinue item attribute on each control.
When you omit the last PPGLayout.EndRow or PPGLayout::EndRow call, all controls from the preceding PPGLayout.AddRow or PPGLayout::AddRow call to the last control on the page will be part of that row.
Unlike group controls, row controls cannot be enumerated and as such do not support any item attributes.