增加图元

   Public Function AddFeature(keyword As String) As Feature
   Dim ftr As New Feature
   Dim addftr As Feature
   ftr.Attach Map1
   ftr.Type = miFeatureTypeSymbol
   ftr.Style = mainlayer.Style
   ftr.Point.Set Map1.CenterX, Map1.CenterY
   Dim ds As Dataset
   Set addftr = mainlayer.AddFeature(ftr)
   mainlayer.KeyField = NameField
   addftr.KeyValue = keyword
   addftr.Update
 
   Set AddFeature = addftr
 End Function