Signature

  object.Linetype

  object

  All Drawing objects, AttributeReference, Group, Layer
  The object this property applies to.

  Linetype

  String; read-write (write-only for the Group object)'仅对Group object可写
  The linetype of an object. The default linetype is the linetype of the layer (BYLAYER).

所以：要改变一个对象的线型，必须把它放入到一个Group中。

例子如下：

Sub Example_Linetype()
    ' This example searches for the linetype DashDot. If it is
    ' not found, it is added from the acad.lin file. Then a
    ' line is created and changed to the DashDot linetype.
   
    ' Search the linetypes collection for the DashDot linetype.
    Dim entry As AcadLineType
    Dim found As Boolean
    found = False
    For Each entry In ThisDrawing.Linetypes
        If StrComp(entry.Name, "DASHDOT", 1) = 0 Then
            found = True
            Exit For
        End If
    Next
    If Not (found) Then ThisDrawing.Linetypes.Load "DASHDOT", "acad.lin"
       
    ' Create the line
    Dim lineObj As AcadLine
    Dim startPoint(0 To 2) As Double
    Dim endPoint(0 To 2) As Double
    startPoint(0) = 1#: startPoint(1) = 1#: startPoint(2) = 0#
    endPoint(0) = 4#: endPoint(1) = 4#: endPoint(2) = 0#
    Set lineObj = ThisDrawing.ModelSpace.AddLine(startPoint, endPoint)
   
    ' Change the linetype of the line
    Set groupObj = ThisDrawing.Groups.Add("TEST_GROUP")

    ReDim appendobjs(0) As AcadEntity
    Set appendobjs(0) = lineObj
    groupObj.AppendItems appendobjs

    groupObj.Linetype = "DASHDOT"

    ThisDrawing.Regen acActiveViewport

End Sub