四舍五入函数

引入math单元

function RoundEx(Value: Extended; RoundMode: TFPURoundingMode = rmUp): Int64;
var
  RM: TFPURoundingMode;
begin
  RM := GetRoundMode;
  try
    SetRoundMode(RoundMode);
    Result := Round(Value);
  finally
    SetRoundMode(RM);
  end;
end;

举例:
i := RoundEx(11.5)    结果: i=12
i := RoundEx(10.5)    结果: i=11
举例:
i := RoundEx(11.5, rmTruncate)    结果: i=11
i := RoundEx(10.5, rmTruncate)    结果: i=10
RoundEx函数华丽的变身为Trunc函数