title: List all Feature Classes in an MXD
body: <p>I have an mxd file that I've loaded into ArcMap. When finished loading, there are several layers; some of which that have multiple feature classes. The end result is listing all the filepaths/locations/source of each feature class, but for now, I just need to know how to list all the feature classes that are loaded. And when I say list, they can really just be output to the screen via message boxes. I know I'll need to loop through each layer, but utilizing the right interface and accessing ArcMaps properties is where I get lost.</p>
  
  <p>Any help on this would be greatly appreciated. I'm still learning ArcObjects and how it all works and in desperate need of help. Thanks in advance.</p>