计算时间并显示为 天-时-分-秒解决办法

计算时间并显示为 天-时-分-秒
var
  i:Extended;
  s:string;
begin
 i:=StrToDateTime('2012-12-30 00:00:00')-StrToDateTime('2011-12-30 12:00:00');
 // s:=?'天'+?'时'+?'分'+?'秒'
end;


------解决方案--------------------
var
iDay, iHour, iMinute, iSecond: integer;
begin
i := Abs(SecondsBetween(StrToDateTime('2012-12-30 00:00:00')-StrToDateTime('2011-12-30 12:00:00')));
iDay := i div 86400;
i := i - (iDay * 86400);
iHour := i div 3600;
i := i - (iHour * 3600);
iMinute := i div 60;
i := i - (iMinute * 60);
iSecond := i;
s:= format('%d天%d时%d分%d秒', [iDay, iHour, iMinute, iSecond]);
end;