多春鱼小屋

procedure DelayUSec(USec : Integer);
var
  Counter,Counter2,Freq:Int64;
  Tim :Double;
begin
  QueryPerformanceFrequency(Freq);
  QueryPerformanceCounter(Counter);
  repeat
    QueryPerformanceCounter(Counter2);
    Tim :=  (Counter2 - Counter) / Freq;
  until not (Tim < USec * 0.000001);
end;