外部参照的问题???

笑傲江湖

各位大侠,大家好,我有一个问题问大家???我想插入一个外部参照的块,并给他附上属性,可是一直不成功,why?
Public Sub arrester()
    Dim attheight As Double
    Dim attmode As Long
    Dim attprompt(0 To 20) As String
    Dim attinspoint(0 To 2) As Double
    Dim atttag(0 To 20) As String
    Dim attvalue(0 To 20) As String
    Dim inputpoint(0 To 2) As Double
    Dim blockname As String
    Dim i As Integer
    Public externalblock   As AcadExternalReference
    Public attriobject As AcadAttribute
    Public blockrefobj As AcadBlockReference
   
   inputpoint(0) = 2
   inputpoint(1) = 2
   inputpoint(2) = 2
   filename = "D:\Program files\ACAD2000\firstside\arrester.dwg" '图块的位置
   blockname = "arrester"
    attheight = 1
    atttmode = acAttributeModeVerify
    attinspoint(0) = 10
    attinspoint(1) = 10
    attinspoint(2) = 0
    atttag(0) = "model"
    atttag(1) = "modelID"
    attprompt(0) = "model"
    attprompt(1) = "modelID"
    attvalue(0) = "arrester"
    attvalue(1) = "111"
    For i = 0 To 1
    Set attriobject = externalblock.AddAttribute(attheight, attmode, attprompt(i), attinspoint, atttag(i), attvalue(i))
    attriobject.Invisible = True
    Next i
   Set externalblock = ThisDrawing.ModelSpace.AttachExternalReference(filename, blockname, inputpoint, 1, 1, 1, 0, False)
End Sub
帮帮忙?why?谢谢