I'm using ArcGIS 10 and the .NET SDK. For each feature in a feature layer, is there a way to selectively flip the feature horizontally? I want to loop through the features, and for each feature decide whether to horizontally flip the feature or not. The features are point symbols. I know how to access to the IFeature interface of each feature. Where do I go from here? Do I need to add a representation rule to the features that I want to flip? Would that work on a per feature basis? Thanks for any help.
The geometries of all features in a point feature layer are a single points so you can't flip the geometry by looping through the IFeatures. It sounds like what you are trying to do is rotate the symbology. For example, if your point features were symbolized with arrows then you could change the rotation property from 90 to 270 to flip them horizontally. IRotationRenderer will allow you rotate by a field in your feature class. Of course this method will only work with symmetrical marker symbols as other symbols would just appear upside-down when rotated. If the markers are more complex then you can use IFeatureRenderer.SymbolByFeature to apply a different symbol to each feature.
Thanks for your suggestions, richwawr. Yes, I'd like to alter the symbology, not the geometry. My symbols are asymmetrical, so I can't just rotate, I have to horizontally flip. Like with a symbol of a flag with a flagpole, I'd like to be able to have the flagpole face either the left side or the right side. Worst case, I could create two different symbols, as you said, but that would double the set of symbols I have to maintain (which I'd like to avoid if at all possible).