How to get selected feature(s) from selection tool?

OscarYam

I would like to create a button that updates the selected feature's attribute. When I started coding, I found that I cannot get the selected feature after I use the default selection tool(the tools under esri_mapping_selectToolPalette). Is it any method to get the selected feature from the default selection tool?

CharlesMacleod

Subscribe to the MapSelectionChangedEvent. Any changes to the map selection via selection tool, via custom selection, etc. will fire the event.

ArcGIS.Desktop.Mapping.Events.MapSelectionChangedEvent.Subscribe((args) => {
   //If u are only interested in one particular map...
   if (args.Map.Name == "The Map Name I am Interested In") {
     System.Diagnostics.Debug.WriteLine("Selection changed");
     var sel = args.Selection;//This is what is selected
     if (sel.Count == 0) {
       System.Diagnostics.Debug.WriteLine(" 0 features selected");
       return;
     }
     //enumerate current selection - a series of keyvalue pairs
     //key is the MapMember, Value is the list of OIDs
     foreach(var kvp in sel.ToDictionary()) {
  
       var oids = kvp.Value; //OIDs of the selected features
       var oid_str_list = oids.Select(oid => oid.ToString()).ToList();
       var oid_str = string.Join(",", oid_str_list);
       System.Diagnostics.Debug.WriteLine(
                     $"{kvp.Key.Name}: {oid_str}");

       if (kvp.Key is BasicFeatureLayer fl) {
         //TODO selection is on a vector layer...
       }
       else if (kvp.Key is StandaloneTable tbl) {
         //TODO selection is on a table...
       }
       //else if (....)
       //{
       //   etc,etc.
       //}
    }
   }
 });

 

Note: In 2.x, the event argument syntax is slightly different. The Selection property is a Dictionary so there is no sel.ToDictionary() as such.