给你另外一个方法。
QueryPerformanceFrequency(c);//得到当前系统cpu频率
// 准确延时。...延时间隔是us.
procedure delay(delay_time:integer);
var t,t1:TLargeInteger;
begin
QueryPerformanceCounter(t);//得到当前cpu工作周期,从开机开始计时
repeat
QueryPerformanceCounter(t1);
until (t1-t)*1000000/c>=delay_time;
end;
