C# Sample:
 
private void WpfMap_Loaded(object sender, RoutedEventArgs e)
        {
            Map1.MapUnit = GeographyUnit.DecimalDegree;
            Map1.Overlays.Add("WMK", new WorldMapKitWmsWpfOverlay());
            Map1.CurrentExtent = new RectangleShape(-155.733, 95.60, 104.42, -81.9);
            
            DrawingFontStyles draingFontStyles = DrawingFontStyles.Bold | DrawingFontStyles.Italic | DrawingFontStyles.Underline;
            GeoFont geoFont = new GeoFont("Arial", 10, draingFontStyles);
            TextStyle textStyle = new TextStyle("textContent", geoFont, new GeoSolidBrush(GeoColor.SimpleColors.Red));

            Feature samplePoint = new Feature(-25, -5);
            samplePoint.ColumnValues.Add("textContent", "Hello World");

            InMemoryFeatureLayer pointLayer = new InMemoryFeatureLayer();
            pointLayer.Open();
            pointLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle = PointStyles.Capital1;
            pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle = textStyle;
            pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle.XOffsetInPixel = 15;
            pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle.PointPlacement = PointPlacement.UpperRight;
            pointLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
            pointLayer.InternalFeatures.Add(samplePoint);
            pointLayer.Columns.Add(new FeatureSourceColumn("textContent", "string", 30));
            pointLayer.Close();

            LayerOverlay pointOverlay = new LayerOverlay();
            pointOverlay.TileType = TileType.SingleTile;
            pointOverlay.Layers.Add(pointLayer);

            Map1.Overlays.Add("fanOverlay", pointOverlay);
            Map1.Refresh();
        }

VB# Sample:

    Private Sub WpfMap_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
        Map1.MapUnit = GeographyUnit.DecimalDegree
        Map1.Overlays.Add("WMK", New WorldMapKitWmsWpfOverlay())
        Map1.CurrentExtent = New RectangleShape(-155.733, 95.6, 104.42, -81.9)

        Dim draingFontStyles As DrawingFontStyles = DrawingFontStyles.Bold Or DrawingFontStyles.Italic Or DrawingFontStyles.Underline
        Dim geoFont As New GeoFont("Arial", 10, draingFontStyles)
        Dim textStyle As New TextStyle("textContent", geoFont, New GeoSolidBrush(GeoColor.SimpleColors.Red))

        Dim samplePoint As New Feature(-25, -5)
        samplePoint.ColumnValues.Add("textContent", "Hello World")

        Dim pointLayer As New InMemoryFeatureLayer()
        pointLayer.Open()
        pointLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle = PointStyles.Capital1
        pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle = textStyle
        pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle.XOffsetInPixel = 15
        pointLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle.PointPlacement = PointPlacement.UpperRight
        pointLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20
        pointLayer.InternalFeatures.Add(samplePoint)
        pointLayer.Columns.Add(New FeatureSourceColumn("textContent", "string", 30))
        pointLayer.Close()

        Dim pointOverlay As New LayerOverlay()
        pointOverlay.TileType = TileType.SingleTile
        pointOverlay.Layers.Add(pointLayer)

        Map1.Overlays.Add("fanOverlay", pointOverlay)
        Map1.Refresh()
    End Sub