topic Re: Feature Layer Count based on layer created from selection in ArcGIS Pro SDK Questions

Feature Layer Count based on layer created from selection

ChrisRobles — Mon, 07 Jul 2025 18:30:15 GMT

Hi,

Is it possible to get the current count of a feature layer without using the underlying feature class or having to iterate through a search and incrementing a counter? I have a layer that was created using a selection and I've tried getting the count of that layer but it only displays the count based on the underlying feature class.

Re: Feature Layer Count based on layer created from selection

Wolf — Thu, 10 Jul 2025 15:24:44 GMT

If you select all features in the newly created layer you can use GetSelection () and the selection count on the layer, otherwise you have to use a RowCursor on the FeatureLayer itself (not on the underlying FeatureClass or Table):

try { // get all feature layers in the current map var map = MapView.Active.Map; if (map == null) { MessageBox.Show("No active map found.", "Error", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Error); return; } var featureLayers = map.GetLayersAsFlattenedList().OfType<FeatureLayer>().ToList(); if (featureLayers.Count == 0) { MessageBox.Show("No feature layers found in the active map.", "Information", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Information); return; } // count rows in each feature layer StringBuilder result = new StringBuilder(); await QueuedTask.Run(() => { foreach (FeatureLayer layer in featureLayers) { // Get the row count for the feature layer // this is not working since it is getting the underlying table (which has all records in // the case where a layer is created with a 'select' clause // long rowCount = layer.GetTable().GetCount(); // create a cursor for the layer (not the table) var rowCursor = layer.Search(); long rowCount = 0; while (rowCursor.MoveNext()) { rowCount++; } result.AppendLine($"{layer.Name}: {rowCount} rows"); } }); // Show the result in a message box MessageBox.Show(result.ToString(), "Row Count Results", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Information); } catch (Exception ex) { MessageBox.Show($"An error occurred: {ex.Message}", "Error", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Error); }

Re: Feature Layer Count based on layer created from selection

ChrisRobles — Fri, 11 Jul 2025 17:07:42 GMT

Thank you for the reply Wolf, is there any way you would suggest doing the count on a layer that has thousands or tens of thousands of features? I think having to select all features or iterating through each row would cause delay.

Re: Feature Layer Count based on layer created from selection

Wolf — Mon, 14 Jul 2025 21:08:04 GMT

I don't see another way, however, i think processing will be fast since the layer data is cached in memory. Here is my sample:

3141 records in 0.017 seconds.

These are the code changes to measure the timing:

// count rows in each feature layer StringBuilder result = new StringBuilder(); await QueuedTask.Run(() => { foreach (FeatureLayer layer in featureLayers) { // Get the row count for the feature layer // this is not working since it is getting the underlying table (which has all records in // the case where a layer is created with a 'select' clause // long rowCount = layer.GetTable().GetCount(); // create a cursor for the layer (not the table) var rowCursor = layer.Search(); long rowCount = 0; var timer = new Stopwatch(); timer.Start(); while (rowCursor.MoveNext()) { rowCount++; } timer.Stop(); var elapsedTime = timer.Elapsed; result.AppendLine($"{layer.Name}: {rowCount} rows {elapsedTime:m\\:ss\\.fff} min."); } }); // Show the result in a message box MessageBox.Show(result.ToString(), "Row Count Results", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Information);

Re: Feature Layer Count based on layer created from selection

ChrisRobles — Fri, 15 Aug 2025 21:18:33 GMT

That worked great thank you!