等待函数（保持界面正常响应）

取自网络

//延时函数，msec 为毫秒

procedure Delay(msec: single);
var
  FirstTickCount: real;
begin
  if msec > 0 then
  begin
    FirstTickCount := GetTickCount();
    FirstTickCount := FirstTickCount + msec;
    while FirstTickCount > GetTickCount() do
      Application.HandleMessage; //关键在这里
  end;
end;

// 测试CPU占用率<1% (CPU i3)


// 等待函数(保持界面正常响应) MSecs为毫秒
procedure WaitTime(MSecs: Integer);
var
  FirstTickCount, Now: Longint;
begin
  FirstTickCount := Windows.GetTickCount();
  repeat
    Now := Windows.GetTickCount();
    Application.ProcessMessages;
  until (Now - FirstTickCount >= MSecs) or (Now < FirstTickCount);
end;

// 测试CPU占用率10% -- 25%  (CPU i3)

// *通过测试，在线程中调用Delay函数，存在线程函数执行中断（不在有任何响应，但主程序仍正常执行）的情况，而调用WaitTime则正常

// 为降低CPU占用率将WaitTime函数代码修改如下：

// 等待函数(保持界面正常响应) MSecs为毫秒
procedure WaitTime(MSecs: Integer);
var
  FirstTickCount, Now: Longint;
begin
  FirstTickCount := Winapi.Windows.GetTickCount();
  repeat
    Sleep(1);  // 避免CPU占用率高
    Application.ProcessMessages;
    Now := Winapi.Windows.GetTickCount();
  until (Now - FirstTickCount >= MSecs) or (Now < FirstTickCount);
end;

// 测试CPU占用率 < 1%  (CPU i3)