c# - Entity Framework 6 SaveChanges() override not consistently detecting changes -

i've extended class in order add last modified timestamp record if there material changes being made it. done code similar this.

here's problem. savechanges() firing both changes, second 1 isn't getting loop: no objects detected needing changes.

however, record does updated ef through base.savechanges() call.

here's extension mastertable:

namespace audittestef {     public interface ihasauditing     {         datetime lastmodifiedon { get; set; }         int lastmodifiedby { get; set; }     }      public partial class mastertable : ihasauditing     {     }      public class audittestentitieswithauditing : audittestentities     {         public int testinguseris = 1;          public override int savechanges()         {             foreach (objectstateentry entry in (this iobjectcontextadapter)                 .objectcontext                 .objectstatemanager                 .getobjectstateentries(entitystate.added | entitystate.modified))             {                 // loop entered first time, not second                 if (entry.isrelationship) continue;                  var lastmodified = entry.entity ihasauditing;                 if (lastmodified == null) continue;                  lastmodified.lastmodifiedon = datetime.utcnow;                 lastmodified.lastmodifiedby = testinguseris;             }              return base.savechanges();         }     } } 

and here's test harness:

[testmethod] public void testmethod1() {     mastertable mtoriginal;     using (var audit = new audittestentitieswithauditing())     {         var message = "hello";         audit.testinguseris = 1;         mtoriginal = new mastertable {textfield = message};         audit.mastertable.add(mtoriginal);         audit.savechanges();         // test passes, testinguser set in override         assert.istrue(mtoriginal.lastmodifiedby == audit.testinguseris);         }      using (var audit = new audittestentitieswithauditing())     {         var mt = audit.mastertable.find(mtoriginal.mastertableid);         mt.textfield = "goodbye";         audit.testinguseris = 4;         audit.savechanges();         // test fails, record written "goodbye"         // getobjectstateentries(entitystate.added | entitystate.modified) has no entries.         assert.istrue(mt.lastmodifiedby == audit.testinguseris);                 } } 

there's no other code. there's no weird turning off/on entity tracking or anything. wysiwyg.

what missing? how modified object being missed check modified?

annnd... answered own question, of course, after talking duck.

    public override int savechanges()     {         changetracker.detectchanges(); 

this fixes everything. thank attention, hope helps else.