Get First Feature from Point Search in GeoFeatureLayer Snippet

///<summary>Finds the first feature in a GeoFeature layer by supplying an point.  The point could come from a mouse click in the map.</summary>
///
///<param name="searchTolerance">A System.Double that is the number of map units to search. Example: 25</param>
///<param name="point">An IPoint interface in map units where the user clicked on the map</param>
///<param name="geoFeatureLayer">An ILayer interface to search upon</param>
///<param name="activeView">An IActiveView interface</param>
/// 
///<returns>An IFeature interface that is the first feature found in the GeoFeatureLayer.</returns>
/// 
///<remarks></remarks>
public ESRI.ArcGIS.Geodatabase.IFeature GetFirstFeatureFromPointSearchInGeoFeatureLayer(System.Double searchTolerance, ESRI.ArcGIS.Geometry.IPoint point, ESRI.ArcGIS.Carto.IGeoFeatureLayer geoFeatureLayer, ESRI.ArcGIS.Carto.IActiveView activeView)
{
  if (searchTolerance < 0 || point == null || geoFeatureLayer == null || activeView == null)
  {
    return null;
  }

  ESRI.ArcGIS.Carto.IMap map = activeView.FocusMap; 

  // Expand the points envelope to give better search results    
  ESRI.ArcGIS.Geometry.IEnvelope envelope = point.Envelope;
  envelope.Expand(searchTolerance, searchTolerance, false);

  ESRI.ArcGIS.Geodatabase.IFeatureClass featureClass = geoFeatureLayer.FeatureClass;
  System.String shapeFieldName = featureClass.ShapeFieldName;

  // Create a new spatial filter and use the new envelope as the geometry    
  ESRI.ArcGIS.Geodatabase.ISpatialFilter spatialFilter = new ESRI.ArcGIS.Geodatabase.SpatialFilterClass();
  spatialFilter.Geometry = envelope;
  spatialFilter.SpatialRel = ESRI.ArcGIS.Geodatabase.esriSpatialRelEnum.esriSpatialRelEnvelopeIntersects;
  spatialFilter.set_OutputSpatialReference(shapeFieldName, map.SpatialReference);
  spatialFilter.GeometryField = shapeFieldName;

  // Do the search
  ESRI.ArcGIS.Geodatabase.IFeatureCursor featureCursor = featureClass.Search(spatialFilter, false);

  // Get the first feature
  ESRI.ArcGIS.Geodatabase.IFeature feature = featureCursor.NextFeature();
  if (!(feature == null))
  {
    return feature;
  }
  else
  {
      return null;
  }
}

'''<summary>Finds the first feature in a GeoFeature layer by supplying an point.  The point could come from a mouse click in the map.</summary>
'''
'''<param name="searchTolerance">A System.Double that is the number of map units to search. Example: 25</param>
'''<param name="point">An IPoint interface in map units where the user clicked on the map</param>
'''<param name="geoFeatureLayer">An ILayer interface to search upon</param>
'''<param name="activeView">An IActiveView interface</param>
''' 
'''<returns>An IFeature interface that is the first feature found in the GeoFeatureLayer.</returns>
''' 
'''<remarks></remarks>
Public Function GetFirstFeatureFromPointSearchInGeoFeatureLayer(ByVal searchTolerance As System.Double, ByVal point As ESRI.ArcGIS.Geometry.IPoint, ByVal geoFeatureLayer As ESRI.ArcGIS.Carto.IGeoFeatureLayer, ByVal activeView As ESRI.ArcGIS.Carto.IActiveView) As ESRI.ArcGIS.Geodatabase.IFeature

  If searchTolerance < 0 OrElse point Is Nothing OrElse geoFeatureLayer Is Nothing OrElse activeView Is Nothing Then

    Return Nothing

  End If

  Dim map As ESRI.ArcGIS.Carto.IMap = activeView.FocusMap

  ' Expand the points envelope to give better search results    
  Dim envelope As ESRI.ArcGIS.Geometry.IEnvelope = point.Envelope
  envelope.Expand(searchTolerance, searchTolerance, False)

  Dim featureClass As ESRI.ArcGIS.Geodatabase.IFeatureClass = geoFeatureLayer.FeatureClass
  Dim shapeFieldName As System.String = featureClass.ShapeFieldName

  ' Create a new spatial filter and use the new envelope as the geometry    
  Dim spatialFilter As ESRI.ArcGIS.Geodatabase.ISpatialFilter = New ESRI.ArcGIS.Geodatabase.SpatialFilterClass
  spatialFilter.Geometry = envelope
  spatialFilter.SpatialRel = ESRI.ArcGIS.Geodatabase.esriSpatialRelEnum.esriSpatialRelEnvelopeIntersects
  spatialFilter.OutputSpatialReference(shapeFieldName) = map.SpatialReference
  spatialFilter.GeometryField = shapeFieldName

  ' Do the search
  Dim featureCursor As ESRI.ArcGIS.Geodatabase.IFeatureCursor = featureClass.Search(spatialFilter, False)

  ' Get the first feature
  Dim feature As ESRI.ArcGIS.Geodatabase.IFeature = featureCursor.NextFeature

  If Not (feature Is Nothing) Then

    Return feature

  Else

    Return Nothing

  End If

End Function