Delphi 的 Round() 四捨五入函數採奇入偶捨方式, Ex:
  Round(1.5) => 2
  Round(2.5) => 3
  Round(3.5) => 4 

解決之道: 自己寫四捨五入函數, 以下提供兩種:

  方法一: 

    function MyRound(P: Double; Decimals: integer): Double;
    var
      factor: LongInt;
      help: Double;
      i: integer;
    begin
      factor := 1;
      for i := 1 to decimals do
        factor := factor * 10;
  
      if P < 0 then
        help := -0.5
      else
        help := 0.5;
      Result := Int(P*factor+help) / factor;
      if (Result > -0.00000001) and (Result < 0.00000001) then
        Result := 0.00;
    end;

  方法二: 利用 FloatToStrF 及 StrToFloat 函數:
    
    function MyRound(P: Double; Decimals: integer): Double;
    var
      s: string;
    begin
      s := FloatToStrF(P, ffFixed, 15, Decimals)
      Result := StrToFloat(s);
    end;

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