Question

delphi 如何获得时间差(相差几天).

var Date1: TDatetime;
Date1:=DateTimePicker2.Date-DateTimePicker1.Date ;
showmessage(Date1);//报错
怎么回事?
请问如何得到一段时间的相距天数?

Answer 1

用DaysBetween计算两日期之间的天数差。要加入DateUtils单元。
uses DateUtils;
var
days:integer;
//////////////////////////
days:=DaysBetween(Date1,Date2);//date1,date2为TDataTime型
showmessage(intTostr(days));//显示要将整数转换为字符串型。

Answer 2

var
Date1: Integer;
begin
Date1:=trunc(DateTimePicker1.Date) - trunc(DateTimePicker2.Date);
showmessage(intTostr(Date1));//要转化成字符串
end;

Answer 3

var
i: Integer;
begin
i:= trunc(DateTimePicker1.Date) - trunc(DateTimePicker2.Date);
ShowMessage(intToStr(i));
end;