Hi Ivan,
I've seen the behavior you described as well, but mostly when aggressively panning by mouse drag.
Attached is an image showing what I see, where the county names are shown twice at slightly different font sizes. The county lines are fine because they belong to features in an InMemoryFeatureLayer. The problem persists even if I collapse the InMemoryFeatureLayer.
When using the zoom bar, two calls are made to GeoTile.axd for the county map each time I click the + or - symbol or slide the zoom bar. After the first call completes, the labels appear correctly. After the second call completes, the duplicate labels appear. I've tried the default zoom levels and custom zoom levels (using Map.SyncClientZoomLevels) and see similar behavior except the font size difference is much greater with the default zoom levels.
Again, the double-label problem only appears when using the zoom bar. The labels appear correctly when panning the map by dragging with a mouse or zooming by shift-drag. In those cases, only a single call to GeoTile.axd is made to refresh the map. Here are a few more details:
Server-side code:
ShapeFileFeatureLayer countyLayer = new ShapeFileFeatureLayer(Server.MapPath("~/App_Data/cb100_poly.shp"));
TextStyle countyTextStyle = TextStyles.CreateSimpleTextStyle("CO_NAME", "Arial", 10, DrawingFontStyles.Regular, GeoColor.StandardColors.Black);
countyLayer.ZoomLevelSet.ZoomLevel10.DefaultTextStyle = countyTextStyle;
countyLayer.ZoomLevelSet.ZoomLevel10.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
ServerLayerOverlay countyLayerOverlay = new ServerLayerOverlay("CountyServerOverlay");
countyLayerOverlay.Layers.Add("CountyLayer", countyLayer);
SilverlightMapConnector1.ServerLayerOverlays.Add(countyLayerOverlay);
Silverlight code:
ServerLayerOverlay countyServerOverlay = new ServerLayerOverlay("CountyServerOverlay", "SilverlightMapConnector1");
countyServerOverlay.TileType = TileType.SingleTile;
Map.Overlays.Add("CountyOverlay", countyServerOverlay);
We're only using the county layer to show labels at this point because we're working with the county polygons as individual features in various InMemoryFeatureLayers. The server overlay is positioned on top of the InMemoryFeatureLayers so the labels appear on top starting at ZoomLevel10.
