CProgressCtrl 사용
You can use the progress control to indicate the progress of a lengthy operation. It is a rectangle that is gradually filled with the system highlight color as the operation progresses.
The progress control is represented in MFC by class CProgressCtrl.
When you initially create the progress control, you specify its size and position, parent window (usually a dialog box), and ID. By using the dwStyle parameter, you can also specify various window styles for the control and styles for how it fills.