public string Build() { var text2 = !string.IsNullOrEmpty(LeaderText2) ? $"_{LeaderText2.ToFixLength(21)}" : ""; var text3 = !string.IsNullOrEmpty(LeaderText3) ? $"_{LeaderText3.ToFixLength(21)}" : ""; return($"{LineCode}_{Birthday.ToFixLength()}_{Sex.ToFixLength(1)}_{LeaderText1.ToFixLength(31)}{text2}{text3}{LF}"); }