Get layer by name

Question

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();

helenchu · Answer

Thank you very much Wolfgang.  It really helps.

Wolf · Answer

The selection is returned as a Dictionary of MapMembers and the list of selected object ids for each MapMember. In order words: Dictionary>. 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"); }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍