Hi,
We are working on an Esri silverlight application (latest versions) -- and are having a problem with how the rotation of a MarkerSymbol works. Basically, the application is a fleet tracking system, where each vehicle has its coordinates reported in real time, along with the direction the vehicle is facing.
We have a GraphicsLayer that contains all of the vehicle symbols, and the symbol has its rotation set using something like...
<Image RenderTransformOrigin="0.5,0.5" Source="{Binding Attributes[ImageLoc]}">
<Image.RenderTransform>
<RotateTransform Angle="{Binding Attributes[Heading]}"/>
</Image.RenderTransform>
</Image>
and...
graphic.Attributes["Heading"] = heading;
That works well, and the units are displayed on the map correctly. However, when the application tries to adjust the positions of the vehicles (which happens every second, let's say) -- it does so by creating a new GraphicsLayer, and filling it with a symbol for each vehicle. The old layer is then removed and the new layer takes its place.
Again -- that works well, except there is a 1 frame flicker -- where all vehicles are drawn pointing Northwards instead of their correct orientation. Does anyone have any advice on how to get this working without that flicker?
Thanks,
-Aaron
PS -- we have tried this several other ways... Having a single layer and adjusting the heading of existing markers does not flicker -- however it takes a long time (1 second or so) -- guessing because it redraws after each marker is updated or something along those lines.
