Delphi四舍五入

//四舍五入 pValue-传入值 pDigit-小数位数,为不小于0的整数
function FloatDigit(pValue: Double; pDigit: Integer): Double;
var
  i: Integer;
  nPos,nDigit: Integer;
  s,sValue: string;
begin
  try
    sValue := FloatToStr(pValue);
    nPos := Pos('.', sValue);
    if nPos <= 0 then
    begin
      Result := pValue;
    end else
    begin
      nDigit := Length(Copy(sValue, nPos + 1, Length(sValue) - nPos));
      if nDigit <= pDigit then
      begin
        Result := pValue;
      end else
      begin
        if StrToInt(Copy(sValue, nPos + pDigit + 1, 1)) < 5 then
        begin
          Result := StrToFloat(Copy(sValue, 1, nPos + pDigit));
        end else
        begin
          s := '0.0';
          for i := 2 to pDigit + 1 do
            s := s + '0';  
          Result := RoundTo(StrToFloat(Copy(sValue, 1, nPos + pDigit + 1)) + StrToFloat(Copy(s, 1, Length(s) - 1) + '1'), -1 * pDigit);