Ghosting and Map Functionality Loss in Map View C# Arcobjects

Question

I'm writing a C# add-in and trying to implement a piece where a user can add points to a graphics layer on the map view. The points are drawing, however the map pane has serious ghosting issues and I lose the ability to scroll zoom in and out. I assume the problem is in the way I am refreshing the display. Any input would be great. Thanks,

protected override void OnMouseDown(MouseEventArgs arg)
    {

        base.OnMouseDown(arg);
        IGeometry pointcreate = drawPoint(ArcMap.Document.ActiveView, arg.X, arg.Y); //This creates the point but does not actually place it on screen
        IRgbColor newColor = new RgbColorClass();
        newColor.Red = 128;
        IMap thisMap = getMap(ArcMap.Application);
        addGraphicToMap(thisMap, pointcreate, newColor,newColor); //this actually places the graphic on screen.
        IPoint newPoint = ScrCoordToMapCoord(arg.X, arg.Y, ArcMap.Document.ActiveView);
        ArcMap.Document.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null); //This is the refresh in question, I think.

}

Answer 1

Anytime you call IScreenDisplay.StartDrawing, be sure you call IScreenDisplay.FinishDrawing, otherwise your display caches can become corrupted. To be safe, consider calling FinishDrawing in an exception handler.