也许很多朋友在做WEB项目的时候都会碰到这样一个需求:当用户上传文件时,需要将上传的文件保存到另外一台专门的文件服务器。
要实现这样一个功能,有两种解决方案:
方案一、在文件服务器上新建一站点,用来接收上传的文件,然后保存。
方案二、将文件服务器的指定目录共享给WEB服务器,用来保存文件。
方案一不用多说,应该是很简单的了,将上传文件的FORM表单的ACTION属性指向文件服务器上的站点即可,我们来重点说下方案二。
也许你会说,其实方案二也很简单,在WEB服务器上做下磁盘映射,然后直接访问不就行了。其实不是这样的,IIS默认账户为NETWORK_SERVICE,该账户是没权限访问共享目录的,所以当你把站点部署到IIS上的时候,再访问映射磁盘就会报“找不到路径”的错误。所以,直接创建磁盘映射是行不通的,我们需要在程序中用指定账户创建映射,并用该账户运行IIS进程,下面来说下详细步骤及相关代码。
1、在文件服务器上创建共享目录,并新建访问账户。
比如共享目录为:\\192.168.0.9\share
访问账户为:user-1 密码为:123456
2、在WEB服务器上新建用户:user-1 密码为:123456,用户组选择默认的user组即可。
3、在WEB项目中新建公共类WNetHelper
01 using System.Runtime.InteropServices;
02
03 public class WNetHelper
04 {
05 [DllImport("mpr.dll", EntryPoint = "WNetAddConnection2")]
06 private static extern uint WNetAddConnection2(NetResource lpNetResource, string lpPassword, string lpUsername, uint dwFlags);
07
08 [DllImport("Mpr.dll", EntryPoint = "WNetCancelConnection2")]
09 private static extern uint WNetCancelConnection2(string lpName, uint dwFlags, bool fForce);
10
11 [StructLayout(LayoutKind.Sequential)]
12 public class NetResource
13 {
14 public int dwScope;
15
16 public int dwType;
17
18 public int dwDisplayType;
19
20 public int dwUsage;
21
22 public string lpLocalName;
23
24 public string lpRemoteName;
25
26 public string lpComment;
27
28 public string lpProvider;
29 }
30
31 /// <summary>
32 /// 为网络共享做本地映射
33 /// </summary>
34 /// <param name="username">访问用户名(windows系统需要加计算机名,如:comp-1\user-1)</param>
35 /// <param name="password">访问用户密码</param>
36 /// <param name="remoteName">网络共享路径(如:\\192.168.0.9\share)</param>
37 /// <param name="localName">本地映射盘符</param>
38 /// <returns></returns>
39 public static uint WNetAddConnection(string username, string password, string remoteName, string localName)
40 {
41 NetResource netResource = new NetResource();
42
43 netResource.dwScope = 2;
44 netResource.dwType = 1;
45 netResource.dwDisplayType = 3;
46 netResource.dwUsage = 1;
47 netResource.lpLocalName = localName;
48 netResource.lpRemoteName = remoteName.TrimEnd('\\');
49 uint result = WNetAddConnection2(netResource, password, username, 0);
50
51 return result;
52 }
53
54 public static uint WNetCancelConnection(string name, uint flags, bool force)
55 {
56 uint nret = WNetCancelConnection2(name, flags, force);
57
58 return nret;
59 }
60 }
4、为IIS指定运行账户user-1
要实现此功能,有两种办法:
a) 在web.config文件中的<system.web>节点下,添加如下配置:<identity impersonate="true" userName="user-1" password="123456" />
b) 在WEB项目中添加公用类LogonImpersonate
01 public class LogonImpersonate : IDisposable
02 {
03 static public string DefaultDomain
04 {
05 get
06 {
07 return ".";
08 }
09 }
10
11 const int LOGON32_LOGON_INTERACTIVE = 2;
12 const int LOGON32_PROVIDER_DEFAULT = 0;
13
14 [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
15 extern static int FormatMessage(int flag, ref IntPtr source, int msgid, int langid, ref string buf, int size, ref IntPtr args);
16
17 [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
18 extern static bool CloseHandle(IntPtr handle);
19
20 [System.Runtime.InteropServices.DllImport("Advapi32.dll", SetLastError = true)]
21 extern static bool LogonUser(
22 string lpszUsername,
23 string lpszDomain,
24 string lpszPassword,
25 int dwLogonType,
26 int dwLogonProvider,
27 ref IntPtr phToken
28 );
29
30 IntPtr token;
31 System.Security.Principal.WindowsImpersonationContext context;
32
33 public LogonImpersonate(string username, string password)
34 {
35 if (username.IndexOf("\\") == -1)
36 {
37 Init(username, password, DefaultDomain);
38 }
39 else
40 {
41 string[] pair = username.Split(new char[] { '\\' }, 2);
42 Init(pair[1], password, pair[0]);
43 }
44 }
45 public LogonImpersonate(string username, string password, string domain)
46 {
47 Init(username, password, domain);
48 }
49 void Init(string username, string password, string domain)
50 {
51 if (LogonUser(username, domain, password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref token))
52 {
53 bool error = true;
54 try
55 {
56 context = System.Security.Principal.WindowsIdentity.Impersonate(token);
57 error = false;
58 }
59 finally
60 {
61 if (error)
62 CloseHandle(token);
63 }
64 }
65 else
66 {
67 int err = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
68
69 IntPtr tempptr = IntPtr.Zero;
70 string msg = null;
71
72 FormatMessage(0x1300, ref tempptr, err, 0, ref msg, 255, ref tempptr);
73
74 throw (new Exception(msg));
75 }
76 }
77 ~LogonImpersonate()
78 {
79 Dispose();
80 }
81 public void Dispose()
82 {
83 if (context != null)
84 {
85 try
86 {
87 context.Undo();
88 }
89 finally
90 {
91 CloseHandle(token);
92 context = null;
93 }
94 }
95 }
96 }
在访问映射磁盘之前首先调用此类为IIS更换运行用户:LogonImpersonate imper = new LogonImpersonate("user-1", "123456");
5、在访问共享目录前,调用WNetHelper.WNetAddConnection,添加磁盘映射
01 public static bool CreateDirectory(string path)
02 {
03 uint state = 0;
04 if (!Directory.Exists("Z:"))
05 {
06 state = WNetHelper.WNetAddConnection(@"comp-1\user-1", "123456", @"\\192.168.0.9\share", "Z:");
07 }
08 if (state.Equals(0))
09 {
10 Directory.CreateDirectory(path);
11 return true;
12 }
13 else
14 {
15 throw new Exception("添加网络驱动器错误,错误号:" + state.ToString());
16 }
17 }
6、完成。
简洁代码就是:
LogonImpersonate imper = new LogonImpersonate("user-1", "123456");
WNetHelper.WNetAddConnection(@"comp-1\user-1", "123456", @"\\192.168.0.9\share", "Z:");
Directory.CreateDirectory(@"Z:\newfolder");
file1.SaveAs(@"Z:\newfolder\test.jpg