WPF - Adding markers to Operational Layers using data from database rather than service

[Kaju]

I want to create markers on my map from a list containing C# objects with latitude and longitude properties, something similar to the following:

class Marker
{
  public int Long { get; set; }
  public int Lat { get; set; }
}

List<Marker> markers = databaseConnection.GetAllMarkers();

// Create Layer from markers
var layer = GetMarkerLayer(markers);

MapView.Map.OperationalLayers.Add(layer);

These markers need to be in a feature inside the "operationalLayers" list as I want to do clustering with them.

From my research, it seems like this is only possible by getting the data from a URL or some kind of service, but I want this functionality to be completely offline and mutable.

Is this possible?  

[Nicholas-Furness · Accepted solution]

The simplest way to do this is to add Graphics to a Graphics Overlay.

See this sample: https://developers.arcgis.com/net/wpf/sample-code/add-graphics-with-renderer/

Look at the MakePointGraphicsOverlay() method.

A Graphic combines a geometry (in this case point) and optionally attributes, and can provide a symbol to determine what it will look like on the map (although you can optionally define a renderer on the Graphics Overlay to provide the symbol, which is what this sample does).

[Kaju]

Thanks for the response Nicholas,

The current solution I have uses the Graphics Overlay functionality already, and I've implemented my own custom clustering with it before clustering officially came out for ArcGIS. It's quite a hacky solution and has its problems. That's why I ideally want to use the official ArcGIS clustering using the operational layers. 

Is it possible to use the official ArcGIS clustering on a graphics overlay? If so, could you point me to a sample?

Thanks Nicholas  

[dotMorten_esri]

Take a look at FeatureCollectionLayer / FeatureCollection for in-memory feature tables as well as just creating your own on on-disk Geodatabase using Geodatabase.Create and CreateTableAsync.

This will allow you to store data in feature tables that you can render using a feature layer and apply cluster rendering to using the FeatureReduction property.

Having said that, GraphicsOverlay also supports FeatureReduction.

[Nicholas-Furness]

Feature Collections are also a great solution, and mean you can put your data anywhere in the operational layers stack (rather than drawn above it, as the graphics overlays are).

Just a couple of things to bear in mind:

• While you can initially populate a FeatureCollectionTable at the Lite license level using one of these constructors, making subsequent changes to those features (adding, editing, or deleting features) uses the editing APIs, which will require a Basic license.
• FeatureCollectionTables are schema-based, defining the fields expected for each feature, whereas GraphicsOverlays don't require that. This could be a good thing or not.

But as Morten mentioned, clustering is supported on Graphics Overlay for point graphics, so perhaps that'll provide what you need.

[Kaju]

Thanks for your help Nicholas,

You mentioned I'd need a basic license for working with Feature Collections and I'm wondering if I'd need a license for the graphics overlay method of implementing feature reduction.

Thanks

[Nicholas-Furness]

A Lite license is all you'll need (it's free).

While you're developing you typically don't use a license, and you see the "Licensed for developer use only" watermark on your map. When it comes time to deploy, you need to use a license. You can learn more here: https://developers.arcgis.com/net/license-and-deployment/