Automatically synchronize display units to match map units

Summary

When you change from one projected coordinate system to another, the display units automatically change to match the map units. However, when you change from a projected coordinate system to a geographic coordinate system, the display units remain in their previous linear units. The following sample script synchronizes the map units and display units whenever you change the data frame's coordinate system.

Procedure

1. Start ArcMap.
2. Click Tools > Macros > Visual Basic Editor.
3. Double-click Normal (Normal.mxt) > ArcMap Objects > This document in the VBA Project window.
4. Copy the following code into the new window.
   
   

   Code:
   Private WithEvents MapActiveViewEvents As Map
   
   Private Function MxDocument_NewDocument() As Boolean
       EventListener
   End Function
   
   Private Function MxDocument_OpenDocument() As Boolean
       EventListener
   End Function
   
   Private Sub EventListener()
       Dim pMxDoc As IMxDocument
       Set pMxDoc = ThisDocument
       Set MapActiveViewEvents = pMxDoc.FocusMap
   End Sub
   
   Private Sub MapActiveViewEvents_SpatialReferenceChanged()
       Dim pMxDoc As IMxDocument
       Set pMxDoc = ThisDocument
       
       Dim pMap As IMap
       Set pMap = pMxDoc.FocusMap
           
       '-- Set display units to be the same as map units
       pMap.DistanceUnits = pMap.MapUnits
   End Sub

   
   
5. Click File > Save normal.mxt.
6. Exit the Visual Basics Editor.
   
   

   Note:
   The above code has been associated with the normal template and responds to the SpatialReferenceChanged event.  It will be initialized the next time you start a new ArcMap document or load a pre-existing document.