Select features in feature layer

Select features in a feature layer.

Use case

Selecting features, whether by query or identify, can be an important step both in editing data and in visualizing results. One possible use case would be to query a feature layer containing street furniture. A query might look for type “bench” and return a list of bench features contained in the features with an attribute of type bench. These might be selected for further editing or may just be highlighted visually.

How to use the sample

Tap on a feature in the map. All features within a given tolerance (in points) of the tap will be selected.

How it works

1. Create a FeatureLayer instance from a portal item (feature layer or feature service) and add it to the map’s operational layers.
2. Create instances of MapViewReader and MapView.
3. Asynchronously identify nearby features at the tapped location from the map view using the MapViewProxy.identify(layer:screenPoint:tolerance:maximumResults:) method.
4. Select all identified features in the feature layer with FeatureLayer.select(features:).

Relevant API

• Feature
• FeatureLayer
• MapViewProxy
• MapViewReader

About the data

This sample uses the Gross Domestic Product Per Capita, 1960-2016 feature service. Only the 2016 GDP values are shown.

Tags

features, layers, select, selection, tolerance