New Post: Very slow Rendering in version 4.9.2

You don't need to call axMap1.Redraw(); after axMap1.AddLayer(sf, true);
And perhaps adding a spatial index might help: http://www.mapwindow.org/documentation/mapwingis4.9/group__shapefile__spatial__index.html
And are you sure your shapefile is valid: http://www.mapwindow.org/documentation/mapwingis4.9/group__shapefile__validation.html

If you keep having trouble can you send me your shapefile?


Thanks,

Paul