AO的标注 没什么反映 奇怪

Public Sub Anno()
        Dim pActiveView As IActiveView
        Dim pDoc As IMxDocument, pMap As IMap
        Dim pGeoLayer As IGeoFeatureLayer
       
        Set pDoc = Application.Document
        Set pMap = pDoc.FocusMap
        Set pActiveView = pDoc.FocusMap
        Set pGeoLayer = pMap.Layer(0)
       '  MsgBox pGeoLayer.Name
        Dim pAnnoProps As IAnnotateLayerPropertiesCollection
        Dim pAnnoLayerProps As IAnnotateLayerProperties
        Dim pPosition As ILineLabelPosition
        Dim pPlacement As ILineLabelPlacementPriorities
        Dim pBasic As IBasicOverposterLayerProperties
        Dim pLabelEngine As ILabelEngineLayerProperties
        Dim pTextSyl As ITextSymbol
       
      Set pAnnoProps = pGeoLayer.AnnotationProperties
         pAnnoProps.Clear
      
       Set pTextSyl = New TextSymbol
       
        Dim pFont As stdole.StdFont
       Set pFont = New stdole.StdFont
        pFont.Name = "verdana"
        pFont.size = 12
        pTextSyl.Font = pFont
         pTextSyl.Color =new  HsvColor(250, 160, 200)
      Set pPosition = New LineLabelPosition
        pPosition.Parallel = False
        pPosition.Perpendicular = True
       Set pPlacement = New LineLabelPlacementPriorities
      Set pBasic = New BasicOverposterLayerProperties
     
        pBasic.FeatureType = esriBasicOverposterFeatureType.esriOverposterPolyline
        pBasic.LineLabelPlacementPriorities = pPlacement
        pBasic.LineLabelPosition = pPosition
      Set pLabelEngine = New LabelEngineLayerProperties
      Set pLabelEngine.Symbol = pTextSyl
     Set pLabelEngine.BasicOverposterLayerProperties = pBasic
        pLabelEngine.Expression = "[44]"
      Set pAnnoLayerProps = pLabelEngine
      pAnnoProps.Add pAnnoLayerProps
        pGeoLayer.DisplayAnnotation = True
    
        pGeoLayer.DisplayField = pLabelEngine.Expression
  
        pActiveView.Refresh