SceneControl中如何添加图形Element？

IGraphicsLayer graphicsLayer = null;

IGraphicsContainer3D graphicsContainer3D = null;



private void AddData_Click(object sender, EventArgs e)

{

IWorkspaceFactory factory = new FileGDBWorkspaceFactoryClass();

IWorkspace wksp = factory.OpenFromFile(@D:\Data.gdb, 0);

IEnumDataset enumDS = wksp.get_Datasets(esriDatasetType.esriDTFeatureClass);

IFeatureClass FC = enumDS.Next() as IFeatureClass;

IFeatureLayer feaLayer = new FeatureLayerClass();

feaLayer.FeatureClass = FC;

feaLayer.Name = 3D Data;

axSceneControl1.Scene.AddLayer(feaLayer as ILayer, false);

axSceneControl1.Scene.SpatialReference = ((IGeoDataset)FC).SpatialReference;



graphicsLayer = axSceneControl1.Scene.BasicGraphicsLayer;

graphicsLayer.Activate(axSceneControl1.Scene as IScreenDisplay);

axSceneControl1.Scene.AddLayer(graphicsLayer as ILayer, true);

}



private void axSceneControl1_OnMouseDown(object sender, ISceneControlEvents_OnMouseDownEvent e)

{

double ValueZ = 0.0;

ICamera pCamara = this.axSceneControl1.Camera;

IRay pRay = pCamara.GetIdentifyRay(e.x, e.y);

IVector3D pVecotor3D = pRay.Vector;

pVecotor3D.Normalize();

double a = (ValueZ - pRay.Origin.Z) / pVecotor3D.ZComponent;

IPoint Pnt = new PointClass();

Pnt.Z = ValueZ;

Pnt.X = pRay.Origin.X + pVecotor3D.XComponent * a;

Pnt.Y = pRay.Origin.Y + pVecotor3D.YComponent * a;

(Pnt as IZAware).ZAware = true;



IElement pElement = new MarkerElementClass();

IRgbColor pColor = new RgbColorClass();

ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();

pMarkerSymbol.Size = 30;

pMarkerSymbol.Color = pColor;

(pElement as IMarkerElement).Symbol = pMarkerSymbol;

pElement.Geometry = Pnt;



if (graphicsLayer != null)

{

graphicsContainer3D = graphicsLayer as IGraphicsContainer3D;

graphicsContainer3D.DeleteAllElements();

graphicsContainer3D.AddElement(pElement);

}

else

{

graphicsLayer = axSceneControl1.Scene.BasicGraphicsLayer;

graphicsContainer3D = graphicsLayer as IGraphicsContainer3D;

graphicsContainer3D.DeleteAllElements();

graphicsContainer3D.AddElement(pElement);

}



axSceneControl1.SceneGraph.RefreshViewers();

}