vba选择集的问题

Dim blk As AcadBlockReference
Private Sub CommandButton1_Click()
'打开一个图幅
If Len(Dir("E:\擦窗机总库\底架总成\180固定方管\513.8.dwg"))  0 Then
ThisDrawing.Application.Documents.Open "E:\擦窗机总库\底架总成\180固定方管\513.8.dwg"
'
Else
MsgBox "指定的文件不存在！"
End If
'选择该对应的主视图
    Dim filterType1(0 To 2) As Integer
    Dim filterData1(0 To 2) As Variant
    Dim ssetObj1 As AcadSelectionSet
    filterType1(0) = 2
    filterData1(0) = "180主视图"
    filterType1(1) = 100
    filterData1(1) = "AcDbBlockReference"
    Set ssetObj1 = CreateSelectionSet("180主视图")
    ssetObj1.SelectOnScreen filterType1, filterData1
    
    If ssetObj1.Count = 0 Then
        ThisDrawing.Utility.Prompt "用户取消放置状态,退出" & vbCrLf
        Exit Sub
    End If
    
    
    
For Each elem In ssetObj1    '把指定动态块过滤出来
    
    Dim vv As Long
   If blk.IsDynamicBlock Then
        ' 获得动态块的自定义特性
        
        dyBlkPropCol = blk.GetDynamicBlockProperties
            
        For vv = 0 To UBound(dyBlkPropCol)
            Set DBlockProperties = dyBlkPropCol(vv)
            
            With DBlockProperties
        If .PropertyName = "底架轨距" Then
           .Value = CDbl(GJ)
         Exit For
         End If
         End With
        Next vv
    
    blk.Update
  End If
    
    
Next
End Sub