Set objacad = GetObject(, "autocad.application")
Dim sset As AcadSelectionSet '定义选择集对象
Dim element As AcadEntity '定义选择集中的元素对象
Set sset = objacad.ActiveDocument.SelectionSets.Add("ss1") '新建一个选择集
sset.Select acSelectionSetPrevious '前一个选择集
sset.SelectOnScreen '提示用户选择