System.Environment.GetFolderPath函数中未开放的枚举参数

System.Environment.GetFolderPath函数可以通过Environment.SpecialFolder枚举参数获取系统特定的目录，比如桌面，我的文档，收藏夹等..但是有部分参数.NetFrameWork2.0并未开放，比如AllUser用户的这些特殊目录。我们可以通过windowsApi函数SHGetFolderPath来获取，如果你能通过Reflector看一下FrameWork代码就明白了。 

代码如下：

using  System;
using  System.Collections.Generic;
using  System.Text;
using  System.Runtime.InteropServices;
namespace  ConsoleApplication1
... {
     class  Program
     ... {
        [DllImport( " shfolder.dll " , CharSet  =  CharSet.Auto)]
         internal   static   extern   int  SHGetFolderPath(IntPtr hwndOwner,  int  nFolder, IntPtr hToken,  int  dwFlags, StringBuilder lpszPath);

         static   void  Main( string [] args)
         ... {
             for  ( int  i  =   0 ; i  <=   255 ; i ++ )
             ... {
                StringBuilder lpszPath  =   new  StringBuilder( 260 );

                SHGetFolderPath(IntPtr.Zero, i, IntPtr.Zero,  0 , lpszPath);

                Console.WriteLine(i.ToString()  +   " : "   +  lpszPath);
            }
            Console.Read();
        }
    }
}

结果如下

0 :C:/Documents and Settings/Administrator/桌面
1 :
2 :C:/Documents and Settings/Administrator/「开始」菜单/程序
3 :
4 :
5 :C:/Documents and Settings/Administrator/My Documents
6 :C:/Documents and Settings/Administrator/Favorites
7 :C:/Documents and Settings/Administrator/「开始」菜单/程序/启动
8 :C:/Documents and Settings/Administrator/Recent
9 :C:/Documents and Settings/Administrator/SendTo
10 :
11 :C:/Documents and Settings/Administrator/「开始」菜单
12 :
13 :C:/Documents and Settings/Administrator/My Documents/My Music
14 :C:/Documents and Settings/Administrator/My Documents/My Videos
15 :
16 :C:/Documents and Settings/Administrator/桌面
17 :
18 :
19 :C:/Documents and Settings/Administrator/NetHood
20 :C:/WINDOWS/Fonts
21 :C:/Documents and Settings/Administrator/Templates
22 :C:/Documents and Settings/All Users/「开始」菜单
23 :C:/Documents and Settings/All Users/「开始」菜单/程序
24 :C:/Documents and Settings/All Users/「开始」菜单/程序/启动
25 :C:/Documents and Settings/All Users/桌面
26 :C:/Documents and Settings/Administrator/Application Data
27 :C:/Documents and Settings/Administrator/PrintHood
28 :C:/Documents and Settings/Administrator/Local Settings/Application Data
29 :
30 :
31 :C:/Documents and Settings/All Users/Favorites
32 :C:/Documents and Settings/Administrator/Local Settings/Temporary Internet Files
33 :C:/Documents and Settings/Administrator/Cookies
34 :C:/Documents and Settings/Administrator/Local Settings/History
35 :C:/Documents and Settings/All Users/Application Data
36 :C:/WINDOWS
37 :C:/WINDOWS/system32
38 :C:/Program Files
39 :C:/Documents and Settings/Administrator/My Documents/My Pictures
40 :C:/Documents and Settings/Administrator
41 :C:/WINDOWS/system32
42 :
43 :C:/Program Files/Common Files
44 :
45 :C:/Documents and Settings/All Users/Templates
46 :C:/Documents and Settings/All Users/Documents
47 :C:/Documents and Settings/All Users/「开始」菜单/程序/管理工具
48 :C:/Documents and Settings/Administrator/「开始」菜单/程序/管理工具
49 :
50 :
51 :
52 :
53 :C:/Documents and Settings/All Users/Documents/My Music
54 :
55 :C:/Documents and Settings/All Users/Documents/My Videos
56 :C:/WINDOWS/resources
57 :
58 :
59 :C:/Documents and Settings/Administrator/Local Settings/Application Data/Microsoft/CD Burning
 

具体意义可以参照Environment.SpecialFolder枚举说明和windows基本常识来理解。