SHGetSpecialFolderLocation

WINSHELLAPI HRESULT WINAPI SHGetSpecialFolderLocation( HWND hwndOwner, int nFolder, LPITEMIDLIST *ppidl); Retrieves the PIDL of a special folder. Returns NOERROR if successful, or an OLE-defined error result otherwise. hwndOwner Handle to the owner window the client should specify if it displays a dialog box or message box. nFolder Value specifying the folder for which to retrieve the location. This parameter can be one of the following values:

CSIDL_ALTSTARTUP　File system directory that corresponds to the user's nonlocalized Startup program group.

CSIDL_APPDATA　File system directory that serves as a common repository for application-specific data.

CSIDL_BITBUCKET　File system directory containing file objects in the user's Recycle Bin. The location of this directory is not in the registry; it is marked with the hidden and system attributes to prevent the user from moving or deleting it.

CSIDL_COMMON_ALTSTARTUP　File system directory that corresponds to the nonlocalized Startup program group for all users.

CSIDL_COMMON_DESKTOPDIRECTORY　File system directory that contains files and folders that appear on the desktop for all users.

CSIDL_COMMON_FAVORITES　File system directory that serves as a common repository for all users' favorite items.

CSIDL_COMMON_PROGRAMS　File system directory that contains the directories for the common program groups that appear on the Start menu for all users.

CSIDL_COMMON_STARTMENU　File system directory that contains the programs and folders that appear on the Start menu for all users.

CSIDL_COMMON_STARTUP　File system directory that contains the programs that appear in the Startup folder for all users.

CSIDL_CONTROLS　Virtual folder containing icons for the Control Panel applications.

CSIDL_COOKIES　File system directory that serves as a common repository for Internet cookies.

CSIDL_DESKTOP　Windows Desktop—virtual folder at the root of the namespace.

CSIDL_DESKTOPDIRECTORY　File system directory used to physically store file objects on the desktop (not to be confused with the desktop folder itself).

CSIDL_DRIVES　My Computer—virtual folder containing everything on the local computer: storage devices, printers, and Control Panel. The folder may also contain mapped network drives.

CSIDL_FAVORITES　File system directory that serves as a common repository for the user's favorite items.

CSIDL_FONTS　Virtual folder containing fonts.

CSIDL_HISTORY　File system directory that serves as a common repository for Internet history items.

CSIDL_INTERNET　Virtual folder representing the Internet.

CSIDL_INTERNET_CACHE　File system directory that serves as a common repository for temporary Internet files.

CSIDL_NETHOOD　File system directory containing objects that appear in the network neighborhood.

CSIDL_NETWORK　Network Neighborhood Folder—virtual folder representing the top level of the network hierarchy.

CSIDL_PERSONAL　File system directory that serves as a common repository for documents.

CSIDL_PRINTERS　Virtual folder containing installed printers.

CSIDL_PRINTHOOD　File system directory that serves as a common repository for printer links.

CSIDL_PROGRAMS　File system directory that contains the user's program groups (which are also file system directories).

CSIDL_RECENT　File system directory that contains the user's most recently used documents.

CSIDL_SENDTO　File system directory that contains Send To menu items.

CSIDL_STARTMENU　File system directory containing Start menu items.

CSIDL_STARTUP　File system directory that corresponds to the user's Startup program group. The system starts these programs whenever any user logs onto Windows NT or starts Windows 95.

CSIDL_TEMPLATES　File system directory that serves as a common repository for document templates.ppidl Address of a pointer to an item identifier list specifying the folder's location relative to the root of the namespace (the desktop). The calling application is responsible for freeing this pointer with the shell'sIMalloc interface (see SHGetMalloc). See also SHGetSpecialFolderPath

中文介绍：

WINSHELLAPI HRESULT WINAPI SHGetSpecialFolderLocation (HWND hwndOwner, int nFolder,LPITEMIDLIST * ppidl); //函数声明

hwndOwner: 指定了"所有者窗口",在调用这个函数是可能出现的对话框或信息框.

nFolder: 是一个整数id，决定哪个目录是待查找目录,它的取值可能是

CSIDL_BITBUCKET 回收站

CSIDL_CONTROLS 控制面板

CSIDL_DESKTOP Windows桌面desktop;

CSIDL_DESKTOPDIRECTORY desktop的目录；

CSIDL_DRIVES 我的电脑

CSIDL_FONTS 字体目录

CSIDL_NETHOOD 网上邻居

CSIDL_NETWORK 网上邻居virtual folder

CSIDL_PERSONAL 我的文档

CSIDL_PRINTERS 打印机

CSIDL_PROGRAMS 程序组

CSIDL_RECENT 最近打开文档

CSIDL_SENDTO 发送到菜单项

CSIDL_STARTMENU 快启菜单

CSIDL_STARTUP 启动目录

CSIDL_TEMPLATES 临时文档

ppidl: pidl地址. SHGetSpecialFolderLocation把地址写到pidl.