ThinkGeo.com    |     Documentation    |     Premium Support

What are overlays and what are they used for

#1

What are overlays, what do they mean, how do I decide what goes in each overlays?
For example my layers usually include some kind of background layer, a few entity layers which are icons shown on different locations on the map and also layers with shapes like polygon, polyline recatngles. Sometimes even layers with labels.
can I just put them all on one overlay?

Thanks.

#2

Hi Gal,

Welcome to our forum. Please check the answers below.

What are overlays?What do they mean?
The overlay is the a group of layers and each layer can be any of layer type, such as, InMemoryFeatureLayer, ShapeFileFeatureLayer, TabFeatureLayer, etc. And in order to get the high performance, the TileCache can be applied to the Overlay. If we want to add the layer to the map, we need to add the layer into some overlays and then add the overlays into map.Overlays. The code maybe like the following:

  LayerOverlay overlay = new LayerOverlay();
  overlay.Layers.Add(layer);
  Map1.Overlays.Add(overlay);

How do I decide what goes in each overlays?
Usually, we put the layers which often changes into one overlay and then we can just refresh the overlay.

Can I just put them all on one overlay?
As I mentioned in the 1st, the layer of any type can be add into the overlay, so we can put all the layer into one overlay, but it based on the real scenario.

Please see more information from our wiki http://wiki.thinkgeo.com/wiki/map_suite_wpf_desktop_edition

Thanks,
Peter

1 Like