The first issue I see is that you are applying an AreaStyle to a PolyLine Shapefile. You might want to change the Style you apply to your Shapfile to a DefaultLineStyle as in the following:myLayer.ZoomLevelSet.ZoomLevel01.DefaultLineStyle = LineStyles.Highway1;
Did you set the CurrentExtent right? I added this code and I can see the lines, Map1.CurrentExtent = layer.GetBoundingBox(); BTW, if you are using the development version and the version is later than 6.0.37.0, you need to add the BaseShape.GeometryLibrary = GeometryLibrary.Managed; to your code, because there are some records are not valid in the shape file. And don't forget to add the code that Ryan provided.