How to prevent automatically redraw the graphic layers on ArcObjects?

Question

After a ShapeFile that was read to IFeatureLayer converted to IGraphicElements, I'm trying to draw that on map (using Sublayer of ICompositeGraphicsLayer). Of course, I succeed to display it on map, however, when I move the map to other position using IScreenDisplay.Pan*(), them automatically redraws.

I want to prevent them redraw. How can I do that?

To solve the above problem, I tried to use ILayer.Cached and IActiveView.PartialRefresh, but I failed.

The sample code is

AxMapControl m_axMapControl;

public AxMapControl getMapControl()
{
  return m_axMapControl;
}

public IActiveView getActiveView()
{
  return getMapControl().ActiveView;
}

public IMap getFocusMap()
{
  return getActiveView().FocusMap;
}

internal static IGraphicElements SelectedFeaturesToGraphics(/*IMap targetMap,*/ IFeatureLayer featureLayer)
{
  var elements = new GraphicElements() as IGraphicElements;

  IGeoFeatureLayer geoFeatureLayer = (IGeoFeatureLayer)featureLayer;
  IFeatureRenderer featureRenderer = geoFeatureLayer.Renderer;

  IQueryFilter queryFilter = new QueryFilter();
  var cursor = featureLayer.FeatureClass.Search(queryFilter, false);

  ISymbol symbol = null;
  switch (featureLayer.FeatureClass.ShapeType)
  {
    case esriGeometryType.esriGeometryPoint:
    case esriGeometryType.esriGeometryMultipoint:
      {
        var s = new SimpleMarkerSymbol();
        s.Style = esriSimpleMarkerStyle.esriSMSCircle;
        s.Size = 2;
        s.Color = GeoUtil.GetIColor(Colors.Black);
        symbol = s as ISymbol;
      }
      break;

    case esriGeometryType.esriGeometryLine:
    case esriGeometryType.esriGeometryPolyline:
      {
        var s = new SimpleLineSymbol();
        s.Color = GeoUtil.GetIColor(Colors.Black);
        s.Style = esriSimpleLineStyle.esriSLSSolid;
        s.Width = 1;
        symbol = s as ISymbol;
      }
      break;

    case esriGeometryType.esriGeometryPolygon:
      {
        var l = new SimpleLineSymbol();
        l.Color = GeoUtil.GetIColor(Colors.Black);
        l.Width = 1;
        l.Style = esriSimpleLineStyle.esriSLSSolid;

        var s = new SimpleFillSymbol();
        s.Color = l.Color;
        s.Style = esriSimpleFillStyle.esriSFSSolid;
        s.Outline = l;
        symbol = s as ISymbol;
      }
      break;
  }

  IFeatureCursor featureCursor = (IFeatureCursor)cursor;
  IFeature feature = featureCursor.NextFeature();
  while (feature != null)
  {
    IGeometry geometry = feature.Shape;
    //ISymbol symbol = featureRenderer.get_SymbolByFeature(feature);
    //string elementName = string.Format("{0}_{1}", featureLayer.Name, feature.OID);
    IElement element = null;

    switch (geometry.GeometryType)
    {
      case esriGeometryType.esriGeometryPoint:
        element = new MarkerElementClass();
        (element as IElement).Geometry = geometry;
        //(element as IMarkerElement).Symbol = symbol as IMarkerSymbol;
        //graphicsCon.AddElement(element, 0);
        break;
      case esriGeometryType.esriGeometryPolyline:
        element = new LineElementClass();
        element.Geometry = geometry;
        //(element as ILineElement).Symbol = symbol as ILineSymbol;
        //graphicsCon.AddElement(element, 0);
        break;
      case esriGeometryType.esriGeometryPolygon:
        element = new PolygonElementClass();
        element.Geometry = geometry;
        //(element as IFillShapeElement).Symbol = symbol as IFillSymbol;
        //graphicsCon.AddElement(element, 0);
        break;
    }
    element.Locked = true;
    elements.Add(element as IGraphicElement);
    feature = featureCursor.NextFeature();
  }
  System.Runtime.InteropServices.Marshal.ReleaseComObject(cursor);

  return elements;
}

public void AddGeometry(string key, IGraphicsElement elements)
{
  ICompositeGraphicsLayer compositeGraphicsLayer = (ICompositeGraphicsLayer)FindLayer(SuperGraphicsLayerID);
  if (compositeGraphicsLayer == null)
  {
    MessageBox.Show("compositeGraphicsLayer is null");
    return;
  }

  var layer = compositeGraphicsLayer.AddLayer(l.Key, null) as ILayer;

  int cnt = graphicElements.Count;
  IElementCollection collection = new ElementCollectionClass();
  for (int i = 0; i < cnt; i++)
  {
    collection.Add(graphicElements.get_Element(i) as IElement);
  }

  layer.Visible = true;
  layer.Cached = true;

  (layer as IGraphicsLayer).Activate(getActiveView().ScreenDisplay);
  (layer as IGraphicsContainer).AddElements(collection, 0);

  //getActiveView().Deactivate();
  //getActiveView().Activate(getActiveView().ScreenDisplay.hWnd);

  getActiveView().ScreenDisplay.Invalidate(null, true, getActiveView().get_ScreenCacheID(esriViewDrawPhase.esriViewGraphics, null));
}

private void onMouseUp()
{
  if (bGrab == true)
  {
    bGrab = false;

    IEnvelope extent = m_focusScreenDisplay.PanStop();

    double distance = Math.Sqrt(Math.Pow(e.x - ptMouseDownOnDisplay.X, 2) + Math.Pow(e.y - ptMouseDownOnDisplay.Y, 2));
    if (distance > 1)
    {
      //Check if user dragged a rectangle or just clicked.
      //If a rectangle was dragged, m_ipFeedback in non-NULL
      if (extent != null)
      {
        m_focusScreenDisplay.DisplayTransformation.VisibleBounds = extent;
        m_focusScreenDisplay.Invalidate(null, true, (short)esriScreenCache.esriNoScreenCache);
      }

      MainFrame.g_Main.AddScene(GetCenterPoint(), getMapControl().ActiveView.Extent);
      return;
    }
  }

}

private void SampleCode()
{
  var elements = SelectedFeaturesToGraphics(readShapeFile("...."));
  AddGeometry("sample", elements); // Automatically redraw when move.
  getMapContrl().AddLayer(readShapeFile("....")); // Didn't redraw again except first time when move.
}