How draw a circle arc into a srcreendisplay

Discussion created by eddixon85 on Aug 3, 2011
Latest reply on Aug 4, 2011 by eddixon85
What's wrog with this code?.....
IPoint from = arcPoints["from"] as IPoint;
IPoint to = arcPoints["to"] as IPoint;
IPoint thru = arcPoints["thru"] as IPoint;
ICircularArc circularArcThreePoint = new CircularArcClass();
IConstructCircularArc construtionCircularArc = circularArcThreePoint as IConstructCircularArc;
construtionCircularArc.ConstructThreePoints(from, thru, to, true);
IScreenDisplay screenDisplay = m_mapControl.ActiveView.ScreenDisplay;
ESRI.ArcGIS.Display.ISimpleFillSymbol simpleFillSymbol = new ESRI.ArcGIS.Display.SimpleFillSymbolClass();
ESRI.ArcGIS.Display.ISymbol symbol = simpleFillSymbol as ESRI.ArcGIS.Display.ISymbol;
ESRI.ArcGIS.Display.IRubberBand rubberBand = new ESRI.ArcGIS.Display.RubberPolygonClass();
screenDisplay.StartDrawing(screenDisplay.hDC, (System.Int16)ESRI.ArcGIS.Display.esriScreenCache.esriNoScreenCache);
ISegment pSeg;
ISegmentCollection polyline;
pSeg = circularArcThreePoint as ISegment;
polyline = new PolylineClass();
screenDisplay.DrawPolyline(polyline as IGeometry);

A try draw an arc circle, and then store in a new feature, but throw the following exception:
COMException was unhandled by user code