Getting a featurelayer from a Geoprocessing result

kenbuja

I am creating a featureclass using the following code.

var result = await CreateLayer(System.IO.Path.GetDirectoryName(output), System.IO.Path.GetFileName(output), "POINT", SR.Wkid);
if (result == null) return;

var featurelayer = ?

    public static async Task<IGPResult> CreateLayer(string path, string featureclassName, string featureclassType, int SR_wkid)
    {
      List<object> arguments = new List<object>
      {
        // store the results in the default geodatabase
        //CoreModule.CurrentProject.DefaultGeodatabasePath,
        path,
        // name of the feature class
        featureclassName,
        // type of geometry
        featureclassType,
        // no template
        "",
        // no z values
        "DISABLED",
        // no m values
        "DISABLED"
      };
      await QueuedTask.Run(() =>
      {
        // spatial reference
        arguments.Add(SpatialReferenceBuilder.CreateSpatialReference(SR_wkid));
      });

      IGPResult result = await Geoprocessing.ExecuteToolAsync("CreateFeatureclass_management", Geoprocessing.MakeValueArray(arguments.ToArray()));
      return result;
    }

CreateLayer automatically adds the featureclass to the map. How do I get a reference to this featurelayer? Is this the only way or can I get it directly from the IGResult?

var fcLayer = MapView.Active.Map.GetLayersAsFlattenedList().Where((l) => l.Name == fcName).FirstOrDefault() as BasicFeatureLayer;

 

Wolf

You can disable the automatic adding of the feature class to the current map by changing the GPExecuteToolFlags.AddOutputsToMap option (which is the default) to GPExecuteToolFlags.None, as shown in the snippet below.  

IGPResult result = await Geoprocessing.ExecuteToolAsync("CreateFeatureclass_management", 
        Geoprocessing.MakeValueArray(arguments.ToArray()), null, null, null, GPExecuteToolFlags.None);

 After this is done, you can add the layer yourself, as shown in my Button 'OnClick' sample below:

protected override async void OnClick()
{
  await CreateFeatureClass("TTT", EnumFeatureClassType.POINT);
}

public enum EnumFeatureClassType
{
  POINT,
  MULTIPOINT,
  POLYLINE,
  POLYGON
}

/// <summary>
/// Create a feature class in the default geodatabase of the project.
/// </summary>
/// <param name="featureclassName">Name of the feature class to be created.</param>
/// <param name="featureclassType">Type of feature class to be created. Options are:
/// <list type="bullet">
/// <item>POINT</item>
/// <item>MULTIPOINT</item>
/// <item>POLYLINE</item>
/// <item>POLYGON</item></list></param>
/// <returns></returns>
public static async Task CreateFeatureClass(string featureclassName, 
  EnumFeatureClassType featureclassType)
{
  List<object> arguments = new List<object>
  {
    // store the results in the default geodatabase
    CoreModule.CurrentProject.DefaultGeodatabasePath,
    // name of the feature class
    featureclassName,
    // type of geometry
    featureclassType.ToString(),
    // no template
    "",
    // no z values
    "DISABLED",
    // no m values
    "DISABLED"
  };
  await QueuedTask.Run(() =>
  {
    // spatial reference
    arguments.Add(SpatialReferenceBuilder.CreateSpatialReference(3857));
  });
  IGPResult result = await Geoprocessing.ExecuteToolAsync("CreateFeatureclass_management", 
    Geoprocessing.MakeValueArray(arguments.ToArray()), null, null, null, GPExecuteToolFlags.None);

  var uri = new Uri(result.ReturnValue);
  var lyr = await QueuedTask.Run<FeatureLayer>(() =>
  {
    var newLayer = LayerFactory.Instance.CreateFeatureLayer(uri,
      MapView.Active.Map, LayerPosition.AddToTop, $@"Lyr-{featureclassName}") as FeatureLayer;
    return newLayer;
  });
  MessageBox.Show($@"Newly added: {lyr.Name}");
}

You can also use the result.ReturnValue GDB  path to find the automatically added layer by comparing all feature layer datasources for the current map.