Get layer by name

helenchu — Tue, 09 Jun 2020 19:17:57 GMT

Hi,

The codes below pick up the first layer. If I want a layername instead of 1st. How do I do that ? Thank you!

// get the currently selected features in the map
var selectedFeatures = ArcGIS.Desktop.Mapping.MapView.Active.Map.GetSelection();

// get the first layer and its corresponding selected feature OIDs
var firstSelectionSet = selectedFeatures.First();

Re: Get layer by name

Wolf — Sun, 12 Dec 2021 09:23:07 GMT

The selection is returned as a Dictionary of MapMembers and the list of selected object ids for each MapMember. In order words: Dictionary<MapMamber, List<long>>. Once you know the inheritance relationship between MapMember and FeatureLayer (in essence that FeatureLayer inherits from MapMember) - this is from the online help:

you can now search the Dictionary returned by GetSelection for the specific FeatureLayer (or MapMember) you are looking for. Below is a button click sample looking to the number of selected records in the 'TestPoints' layer.

protected override async void OnClick()
{
  var map = MapView.Active?.Map;
  if (map == null) return ;
  var layerName = "TestPoints";
  var searchThisLayer = map.GetLayersAsFlattenedList().OfType<FeatureLayer>().Where(l => l.Name.Equals(layerName, StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
  if (searchThisLayer == null)
  {
    MessageBox.Show($@"Cannot find this layer: {layerName}");
    return;
  }
  var noIds = await QueuedTask.Run<List<long>>(() =>
  {
    // this returns a dictionary of MapMembers and a list of ObjectIDS for that MapMember's selection
    // Here is helps to know that a FeatureLayer inherits from BasicFeatureLayer, which inherits
    // from Layer, which inherits from MapMember
    // So if we are looking only for one FeatureLayer's selection then we can use 'searchThisLayer'
    // to check the return dictionary of MapMembers
    var listOfMapMemberDictionaries = MapView.Active.Map.GetSelection();
    if (!listOfMapMemberDictionaries.ContainsKey(searchThisLayer as MapMember))
    {
      // Selection Dictionary doesn't a 'searchThisLayer' MapMember 
      return new List<long>();
    }
    return listOfMapMemberDictionaries[searchThisLayer as MapMember];
  });
  MessageBox.Show($@"This layer: {searchThisLayer.Name} has {noIds.Count} selected items");
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Get layer by name

helenchu — Wed, 10 Jun 2020 17:48:25 GMT

Thank you very much Wolfgang. It really helps.

topic Re: Get layer by name in ArcGIS Pro SDK Questions

Get layer by name

Re: Get layer by name

Re: Get layer by name