''''''安全创建选择集
On Error Resume Next
Dim SSet As AcadSelectionSet
If Not IsNull(docObj.SelectionSets.Item("Example")) Then
Set SSet = docObj.SelectionSets.Item("Example")
SSet.Delete '及时删除不用的选择集非常重要
End If
Set SSet = docObj.SelectionSets.Add("Example")
''''''向选择集中添加实体
SSet.Select acSelectionSetCrossing, ptMin, ptMax
''''''将选择集中的实体添加到数组中
Dim objCollection() As Object
ReDim objCollection(SSet.Count - 1)
Dim i As Integer
For i = 0 To SSet.Count - 1
Set objCollection(i) = SSet.Item(i)
Next i