问如何从SQL Server 2008错误码中识别主键重复？

EN

try
{
    db.InsertProcedureCall(id);
}
catch (SqlException e0)
{
   // Won't catch
}
catch (EntityCommandExecutionException e1)
{
    // Will catch
    var se = e1.InnerException as SqlException;
    var code = se.Number;
}
catch (Exception e2)
{
   // if the Entity catch is removed, this will work too
    var se = e2.InnerException as SqlException;
    var code = se.Number;
}

using System.Data.Entity.Infrastructure;
using System.Data.SqlClient;
.........

 try{
    abc...
    }
    catch (DbUpdateException ex)
                {
                    if (ex.InnerException.InnerException is SqlException sqlEx && sqlEx.Number == 2601)
                    {
                        return ex.ToString();
                    }
                    else
                    {
                        throw;
                    }
                }