Create Graphic Buffers around Selected Features Snippet (ArcObjects .NET 10.6 SDK)
ArcObjects Library Reference

Create Graphic Buffers around Selected Features Snippet

Draws graphic buffers around the selected features in the map using distance units specified.

[C#]
///<summary>Draws graphic buffers around the selected features in the map using distance units specified.</summary>
///
///<param name="activeView">An IActiveView interface.</param>
///<param name="distance">A System.Double that is the distance in map units around the select features to draw a graphic buffer. Example: 10</param>
/// 
///<remarks></remarks>
public void CreateGraphicBuffersAroundSelectedFeatures(ESRI.ArcGIS.Carto.IActiveView activeView, System.Double distance)
{
  //parameter check
  if (activeView == null || distance < 0)
  {
    return;
  }
  ESRI.ArcGIS.Carto.IMap map=activeView.FocusMap;
  // Clear any previous buffers from the screen
  ESRI.ArcGIS.Carto.IGraphicsContainer graphicsContainer=(ESRI.ArcGIS.Carto.IGraphicsContainer)map; // Explicit Cast
  graphicsContainer.DeleteAllElements();

  // Verify there is a feature(s) selected
  if (map.SelectionCount == 0)
  {
    return;
  }

  // Reset to the first selected feature
  ESRI.ArcGIS.Geodatabase.IEnumFeature enumFeature=(ESRI.ArcGIS.Geodatabase.IEnumFeature)map.FeatureSelection; // Explicit Cast
  enumFeature.Reset();
  ESRI.ArcGIS.Geodatabase.IFeature feature=enumFeature.Next();

  // Buffer all the selected features by the buffer distance and create a new polygon element from each result
  ESRI.ArcGIS.Geometry.ITopologicalOperator topologicalOperator;
  ESRI.ArcGIS.Carto.IElement element;
  while (!(feature == null))
  {
    topologicalOperator=(ESRI.ArcGIS.Geometry.ITopologicalOperator)feature.Shape; // Explicit Cast
    element=new ESRI.ArcGIS.Carto.PolygonElementClass();
    element.Geometry=topologicalOperator.Buffer(distance);
    graphicsContainer.AddElement(element, 0);
    feature=enumFeature.Next();
  }

  activeView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGraphics, null, null);
}
[Visual Basic .NET]
'''<summary>Draws graphic buffers around the selected features in the map using distance units specified.</summary>
'''
'''<param name="activeView">An IActiveView interface.</param>
'''<param name="distance">A System.Double that is the distance in map units around the select features to draw a graphic buffer. Example: 10</param>
''' 
'''<remarks></remarks>
Public Sub CreateGraphicBuffersAroundSelectedFeatures(ByVal activeView As ESRI.ArcGIS.Carto.IActiveView, ByVal distance As System.Double)

  'parameter check
  If activeView Is Nothing OrElse distance < 0 Then
    Return
  End If

  Dim map As ESRI.ArcGIS.Carto.IMap=activeView.FocusMap
  ' Clear any previous buffers from the screen
  Dim graphicsContainer As ESRI.ArcGIS.Carto.IGraphicsContainer=CType(map, ESRI.ArcGIS.Carto.IGraphicsContainer) ' Explicit Cast
  graphicsContainer.DeleteAllElements()

  ' Verify there is a feature(s) selected
  If map.SelectionCount=0 Then
    Return
  End If

  ' Reset to the first selected feature
  Dim enumFeature As ESRI.ArcGIS.Geodatabase.IEnumFeature=CType(map.FeatureSelection, ESRI.ArcGIS.Geodatabase.IEnumFeature) ' Explicit Cast
  enumFeature.Reset()
  Dim feature As ESRI.ArcGIS.Geodatabase.IFeature=enumFeature.Next()

  ' Buffer all the selected features by the buffer distance and create a new polygon element from each result
  Dim topologicalOperator As ESRI.ArcGIS.Geometry.ITopologicalOperator
  Dim element As ESRI.ArcGIS.Carto.IElement
  Do While Not (feature Is Nothing)
    topologicalOperator=CType(feature.Shape, ESRI.ArcGIS.Geometry.ITopologicalOperator) ' Explicit Cast
    element=New ESRI.ArcGIS.Carto.PolygonElementClass()
    element.Geometry=topologicalOperator.Buffer(distance)
    graphicsContainer.AddElement(element, 0)
    feature=enumFeature.Next()
  Loop

  activeView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGraphics, Nothing, Nothing)

End Sub

Additional Requirements
  • The code in this document requires the following References added to the Visual Studio project:
  • ESRI.ArcGIS.Carto
  • ESRI.ArcGIS.Geodatabase
  • ESRI.ArcGIS.Geometry
  • ESRI.ArcGIS.System