How to control which Fields are exported in ArcObjects? (via Field Mapping)

Question

In ArcMap 10.x, if you use the Export Data command on a layer that has hidden/disabled fields, those fields will not be present in the created feature class/table. My question is simple: how do you duplicate this functionality using ArcObjects and C#? The IField interface seems to have no property or method for defining this aspect of table data. Can it be done?

I am seeking to do this so I can extract a subset of fields from a table and keep it for later use (as opposed to having to deal with all the unnecessary data bloat present in many standardized data releases).

UPDATE: I am currently attempting to use the IFieldInfo option suggested in the comments below, but I find myself unable to perform the conversion from an IFeatureClass to an IFeatureLayer that seems necessary to access ITableFields. Am I missing something? I am doing this in a WinForms app, so there is no parent ArcMap instance open to obtain layer information from. I wish to only work with feature classes and tables, if possible.

UPDATE 2: It would seem that, because this winforms is detached from any instance of ArcMap, I cannot make use of IFeatureLayer to turn fields on and off before exporting. Does anyone know how to properly create a field map object in C#?

• Kirk Kuykendall: Regarding update 2, did you try creating a featurelayer, assigning the featureclass to IFeaturelayer.Featureclass, then set the visibility via ITableFields, then do the export ?
• Nathanus: No, I haven't. Worth a shot, but for now, that method is no longer my preferred one.

Answer 1

I've not written this all the way out but think I see a path. You can check the IFieldInfo2.Visible. Once you have determined what fields are visible then you could do the export. For example you could create a QueryFilter and set its SubFields property and then use IExportOperation passing in the QueryFilter.

• Nathanus: IFieldInfo2.... Genius! I will try that now. It will take me about 30 years (or maybe a few hours) to implement this so I will get back to you tomorrow.
• Nathanus: Ho hum, how would you get to the IFieldInfo2 interface when starting with a feature class? It seems to want an ITable.
• Nathanus: All right, it seems that I can get IFieldInfo from ITableFields, but the latter interface only cooperates with feature layers, not feature classes. I know how to go from class to layer, but can you go backwards?
• blah238: "Hidden" fields are a concept that applies only to feature layers and table views, not feature classes or standalone tables. I think you will need to revisit how you are determining which fields to keep since you aren't using layers.
• Nathanus: Hm, I suppose a Merge Field Map will do the trick.