EntityFramework保存数据库是因字段限制抛出异常如何捕获

catch (DbEntityValidationException ex)
                {
                    StringBuilder errors = new StringBuilder();
                    IEnumerable<DbEntityValidationResult> validationResult = ex.EntityValidationErrors;
                    foreach (DbEntityValidationResult sr in validationResult)
                    {
                        ICollection<DbValidationError> validationError = sr.ValidationErrors;
                        foreach (DbValidationError err in validationError)
                        {
                            errors.Append(err.PropertyName + ":" + err.ErrorMessage + "
");
                        }
                    }                   
                }

EntityFramework保存数据库是因字段限制抛出异常如何捕获