此解决方案适用于
a）自上次在Windows中输入以来的时间
每次鼠标移动或键盘输入都会将时间重置为零。

function GetTimeSinceLastUserInputInWindows(): TTimeSpan;
var
   lastInput: TLastInputInfo;
   currentTickCount: DWORD;
   millisecondsPassed: Double;
begin
  lastInput := Default(TLastInputInfo);
  lastInput.cbSize := SizeOf(TLastInputInfo);

  Win32Check( GetLastInputInfo(lastInput) );
  currentTickCount := GetTickCount();

  if (lastInput.dwTime > currentTickCount) then begin // lastInput was before 49.7 days but by now, 49.7 days have passed
    millisecondsPassed :=
      (DWORD.MaxValue - lastInput.dwTime)
      + (currentTickCount * 1.0); // cast to float by multiplying to avoid DWORD overflow
    Result := TTimeSpan.FromMilliseconds(millisecondsPassed);
  end else begin
    Result := TTimeSpan.FromMilliseconds(currentTickCount - lastInput.dwTime );
  end;
end;

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