我本来以为是通过::SetCurrentDirectory()来设置，结果不是。
看了一下MSDN，里面说Windows 2000 or later: 1.If lpstrFile contains a path, that path is the initial directory.
2.Otherwise, lpstrInitialDir specifies the initial directory.
3.Otherwise, if the application has used an Open or Save As dialog box in the past, the path most recently used is selected as the initial directory. However, if an application is not run for a long time, its saved selected path is discarded. 这个lpstrInitialDir的值能直接改变吗？不能的话，第3点里面说的the path most recently used is selected as the initial directory. 那个path存在什么地方？
看了一下MSDN，里面说Windows 2000 or later: 1.If lpstrFile contains a path, that path is the initial directory.
2.Otherwise, lpstrInitialDir specifies the initial directory.
3.Otherwise, if the application has used an Open or Save As dialog box in the past, the path most recently used is selected as the initial directory. However, if an application is not run for a long time, its saved selected path is discarded. 这个lpstrInitialDir的值能直接改变吗？不能的话，第3点里面说的the path most recently used is selected as the initial directory. 那个path存在什么地方？
dlg.m_fon.lpstrInitialDir == "C:\\";
dlg.DoModal()