Hi Asaf,

Thanks for posting.

Regarding this issue, we can use C# "is" operator to determine if
e.Exception is of type ConstraintException. Code snippet listed below:

   if ((e.Exception) is ConstraintException)
   {
       DataGridView view = (DataGridView)sender;
       view.Rows[anError.RowIndex].ErrorText = "an Constraint error";
       view.Rows[anError.RowIndex].Cells[e.ColumnIndex].ErrorText = "an
Constraint error";
       e.ThrowException = false;
   }//what ever statement you like

Hope this helps!

Best regards,
Jeffrey Tan
Microsoft Online Partner Support