Can someone confirm that code snippet 1 from 2.0 has the same affect as code snippet 2, from 2.5? In both cases, what I'm trying to do is create an event that canceling the editing of any properties.

The only difference is that target.RejectChanges() was replaced with BeginEdit() / CancelEdit() calls.

Thank you !!!

Code Snippet 1 - LLBLGen2.0

entity.PropertyChanged += delegate( object sender, PropertyChangedEventArgs e )
      {
          IEntity2 obj = sender as IEntity2;

          if (obj != null)
          {
              IEntityField2 target = obj.Fields[e.PropertyName];
              target.RejectChange();
          }
      };

Code Snippet 2 - LLBLGen2.5

entity.BeginEdit();
entity.PropertyChanged += delegate( object sender, PropertyChangedEventArgs e )
      {
          IEntity2 obj = sender as IEntity2;
        
          if (obj != null)
          {
              IEntityField2 target = obj.Fields[e.PropertyName];
              target.CancelEdit();
          }
      };

I think I could also set the value back to the original value from the DBValue, which is what I think the underlining code does.

Guidlines to what's best is appreciated.

obj.Fields[e.PropertyName].CurrentValue = obj.Fields[e.PropertyName].DbValue;

If I'm not wrong you can still use RejectChange method. CancelEdit is used to control-databinding purposes.

The docs say that RejectChange was moved to internal/private, and my code isn't compiling with it.

I didn't explore why it didn't compile, I just know it didn't and started looking for alternatives.

You should use SaveFields() and RollbackFields() for field versioning/rollback.