Delphi中獲取時間戳通常使用GetTickCount函數,但是在該函數在毫秒級別是非連續的,通常會間隔15-16毫秒進行跳躍。例如以下代碼
procedure TForm1.btn2Click(Sender: TObject);
var
i: Cardinal;
LastTime, CurTime: Cardinal;
begin
i := 0;
LastTime := GetTickCount;
while True do
begin
if i > 10 then
Break;
CurTime := GetTickCount;
if CurTime <> LastTime then
begin
LastTime := CurTime;
Inc(i);
mmo1.Lines.Add('CurTime' + IntToStr(CurTime));
end;
end;
end;
輸出如下:
CurTime268143831
CurTime268143847
CurTime268143862
CurTime268143878
CurTime268143894
CurTime268143909
CurTime268143925
CurTime268143940
CurTime268143956
CurTime268143972
CurTime268143987
所以在比較小的時間控制之下,使用GetTickCount是不合適的。
一種其他的解決辦法是使用now函數。
procedure TForm1.btn1Click(Sender: TObject);
var
i: Cardinal;
LastTime, CurTime: TDateTime;
time: TTimeStamp;
begin
i := 0;
LastTime := Now;
while True do
begin
if i > 10 then
Break;
CurTime := now;
if CurTime <> LastTime then
begin
LastTime := CurTime;
time := DateTimeToTimeStamp(CurTime);
Inc(i);
mmo1.Lines.Add('CurTime' + FormatDateTime('yyyy-mm-dd hh:mm:ss:zzz', CurTime) + ' [' + IntToStr(time.Time) + ']');
end;
end;
end;
以上代碼輸出如下:
CurTime2019-11-07 11:38:52:317 [41932317]
CurTime2019-11-07 11:38:52:318 [41932318]
CurTime2019-11-07 11:38:52:319 [41932319]
CurTime2019-11-07 11:38:52:320 [41932320]
CurTime2019-11-07 11:38:52:321 [41932321]
CurTime2019-11-07 11:38:52:322 [41932322]
CurTime2019-11-07 11:38:52:323 [41932323]
CurTime2019-11-07 11:38:52:324 [41932324]
CurTime2019-11-07 11:38:52:327 [41932327]
CurTime2019-11-07 11:38:52:328 [41932328]
CurTime2019-11-07 11:38:52:329 [41932329]
即使用TTimeStamp時,非跨天可以直接使用TTimeStamp.Time直接判斷。