public static void SetSnapModes( 
   IEnumerable<SnapMode> modes
)

Snapping.SetSnapModes(new[]{ SnapMode.Midpoint }); // sets only the Midpoint snapping mode 
Snapping.SetSnapModes(new[]{ SnapMode.Point, SnapMode.Edge }); // sets only Point and Edge snapping modes
Snapping.SetSnapModes(null); //clear all snap modes

// set only Point and Edge snapping modes, clear everything else
//At 2.x - ArcGIS.Desktop.Mapping.Snapping.SetSnapModes(SnapMode.Point, SnapMode.Edge);
ArcGIS.Desktop.Mapping.Snapping.SetSnapModes(
  new List<SnapMode>() { SnapMode.Point, SnapMode.Edge });

// clear all snap modes
//At 2.x - ArcGIS.Desktop.Mapping.Snapping.SetSnapModes();
ArcGIS.Desktop.Mapping.Snapping.SetSnapModes(null);


// set snap modes one at a time
ArcGIS.Desktop.Mapping.Snapping.SetSnapMode(SnapMode.Edge, true);
ArcGIS.Desktop.Mapping.Snapping.SetSnapMode(SnapMode.End, true);
ArcGIS.Desktop.Mapping.Snapping.SetSnapMode(SnapMode.Intersection, true);

// get current snap modes
var snapModes = ArcGIS.Desktop.Mapping.Snapping.SnapModes;

// get state of a specific snap mode
bool isOn = ArcGIS.Desktop.Mapping.Snapping.GetSnapMode(SnapMode.Vertex);