C#访问远程主机资源的方法

实现访问远程主机的共享目录中的一个文件的解决方法：一、调用Net use命令 // 使用方法： //if (Connect("192.168.1.48", "用户名", "密码")) //{ // File.Copy(@"//192.168.1.48/共享目录/test.txt", @"e://test.txt", true); //} public bool Connect(string remoteHost, string userName, string passWord) { bool Flag = true; PRocess proc = new Process(); proc.StartInfo.FileName = "cmd.exe"; proc.StartInfo.UseShellExecute = false; proc.StartInfo.RedirectStandardInput = true; proc.StartInfo.RedirectStandardOutput = true; proc.StartInfo.RedirectStandardError = true; proc.StartInfo.CreateNoWindow = true; try { proc.Start(); string command =@"net use //" + remoteHost + " " + passWord + " " + " /user:" + userName + ">NUL"; proc.StandardInput.WriteLine(command); command = "exit"; proc.StandardInput.WriteLine(command); while (proc.HasExited == false) { proc.WaitForExit(1000); } string errormsg = proc.StandardError.ReadToEnd(); if (errormsg != "") Flag = false; proc.StandardError.Close(); } catch (Exception ex) { Flag = false; } finally { proc.Close(); proc.Dispose(); } return Flag; }二、调用WNetAddConnection2、WNetAddConnection3或者NetUseAdd函数，进行磁盘映射。using System;using System.Collections.Generic;using System.Text;using System.Runtime.InteropServices;

namespace Windowsapplication1{ public class MyMap { [DllImport("mpr.dll", EntryPoint = "WNetAddConnection2")] public static extern uint WNetAddConnection2( [In] NETRESOURCE lpNetResource, string lpPassword, string lpUsername, uint dwFlags); [DllImport("Mpr.dll")] public static extern uint WNetCancelConnection2( string lpName, uint dwFlags, bool fForce); [StructLayout(LayoutKind.Sequential)] public class NETRESOURCE { public int dwScope; public int dwType; public int dwDisplayType; public int dwUsage; public string LocalName; public string RemoteName; public string Comment; public string Provider; }

// remoteNetworkPath format: @"//192.168.1.48/sharefolder" // localDriveName format: @"E:" public static bool CreateMap(string userName, string password, string remoteNetworkPath, string localDriveName) { NETRESOURCE myNetResource = new NETRESOURCE(); myNetResource.dwScope = 2; //2:RESOURCE_GLOBALNET myNetResource.dwType = 1; //1:RESOURCETYPE_ANY myNetResource.dwDisplayType = 3; //3:RESOURCEDISPLAYTYPE_GENERIC myNetResource.dwUsage = 1; //1: RESOURCEUSAGE_CONNECTABLE myNetResource.LocalName = localDriveName; myNetResource.RemoteName = remoteNetworkPath; myNetResource.Provider = null;

uint nret = WNetAddConnection2(myNetResource, password, userName, 0);

if (nret == 0) return true; else return false; }

// localDriveName format: @"E:" public static bool DeleteMap(string localDriveName) { uint nret = WNetCancelConnection2(localDriveName, 1, true);

if (nret == 0) return true; else return false; }

public void test() {// 注意： // remote、local、username的格式一定要正确，否则可能出现错误 string remote =@"//192.168.1.48/generals"; string local =@"P:"; string username =@"Domain/UserName"; string password =@"Password"; bool ret = MyMap.CreateMap(username, password, remote, local); if (ret) { //do what you want:// ... //File.Copy("q://test.htm", "c://test.htm");

MyMap.DeleteMap(local); } } }}三、使用WebClient类由于WebClient类可以上传下载文件，并且支持以http:、https:和file:开头的URI，所以可以用WebClient类来传输文件。添加System.Net命名空间后使用如下代码下载文件：

private void Test1() { try { WebClient client = new WebClient(); NetworkCredential cred = new NetworkCredential("username", "password", "172.16.0.222"); client.Credentials = cred; client.DownloadFile("file://172.16.0.222/test/111.txt", "111.txt"); } catch (Exception ex) {//如果网络很慢，而文件又很大，这时可能有超时异常（Timeout）。 } }

public void Test2() { try { WebClient client = new WebClient(); NetworkCredential cred = new NetworkCredential("username", "password", "domain"); client.Credentials = cred; client.DownloadFile("file://172.16.0.222/test/111.txt", "111.txt"); } catch (Exception ex) { //如果网络很慢，而文件又很大，这时可能有超时异常（Timeout）。 } }

类似的还可以试试WebRequest、FileWebRequest等： WebRequest req = WebRequest.Create("file://138.12.12.14/generals/test.htm"); NetworkCredential cred = new NetworkCredential("username", "password", "ip"); req.Credentials = cred; WebResponse response = req.GetResponse(); Stream strm = response.GetResponseStream(); StreamReader r = new StreamReader(strm);... ...四、角色模拟using System;using System.Collections.Generic;using System.Text;using System.Runtime.InteropServices;using System.Security.Principal;using System.IO;

namespace Test{ public class Test { // logon types const int LOGON32_LOGON_INTERACTIVE = 2; const int LOGON32_LOGON_NETWORK = 3; const int LOGON32_LOGON_NEW_CREDENTIALS = 9; // logon providers const int LOGON32_PROVIDER_DEFAULT = 0; const int LOGON32_PROVIDER_WINNT50 = 3; const int LOGON32_PROVIDER_WINNT40 = 2; const int LOGON32_PROVIDER_WINNT35 = 1;

[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] public static extern int LogonUser(String lpszUserName, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, ref IntPtr phToken);

[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] public static extern int DuplicateToken(IntPtr hToken, int impersonationLevel, ref IntPtr hNewToken);

[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] public static extern bool RevertToSelf();

[DllImport("kernel32.dll", CharSet = CharSet.Auto)] public static extern bool CloseHandle(IntPtr handle);

private WindowsImpersonationContext impersonationContext;

public bool impersonateValidUser(String userName, String domain, String password) { WindowsIdentity tempWindowsIdentity; IntPtr token = IntPtr.Zero; IntPtr tokenDuplicate = IntPtr.Zero;

if (RevertToSelf()) {// 这里使用LOGON32_LOGON_NEW_CREDENTIALS来访问远程资源。// 如果要（通过模拟用户获得权限）实现服务器程序，访问本地授权数据库可// 以用LOGON32_LOGON_INTERACTIVE if (LogonUser(userName, domain, password,LOGON32_LOGON_NEW_CREDENTIALS, LOGON32_PROVIDER_DEFAULT, ref token) != 0) { if (DuplicateToken(token, 2, ref tokenDuplicate) != 0) { tempWindowsIdentity = new WindowsIdentity(tokenDuplicate); impersonationContext = tempWindowsIdentity.Impersonate(); if (impersonationContext != null) { System.AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal); IPrincipal pr = System.Threading.Thread.CurrentPrincipal; IIdentity id = pr.Identity; CloseHandle(token); CloseHandle(tokenDuplicate); return true; } } } }

if (token != IntPtr.Zero) CloseHandle(token);

if (tokenDuplicate != IntPtr.Zero) CloseHandle(tokenDuplicate);

return false; }

public void undoImpersonation() { impersonationContext.Undo(); }

public void TestFunc() { bool isImpersonated = false; try { if (impersonateValidUser("UserName", "Domain", "Password")) { isImpersonated = true; //do what you want now, as the special user // ... File.Copy(@"//192.168.1.48/generals/now.htm", "c://now.htm", true); } } finally { if (isImpersonated) undoImpersonation(); } } }}五、比较方法一通过调用Shell命令Net Use实现，有点笨拙。方法二和方法一有些相似之处。映射远程资源，然后访问。方法三由于会有超时异常出现，所以在网络速度快、传输小文件时是可以的。方法四通过身份模拟实现远程资源访问。一些服务器进程就是通过这种方式运行的。这种方法也是我的最爱。六、要注意的地方关于这几种方法，google后都可以找到一些文章。但是等到自己实际测试时，有时会出现各种小错误，这些错误基本来源于两方面：1、函数的参数选择有问题，和自己的环境不相符。比如public static extern int LogonUser(String lpszUserName, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, ref IntPtr phToken);中的dwLogonType，要访问远程资源就要用LOGON32_LOGON_NEW_CREDENTIALS，要模拟本机用户就要用LOGON32_LOGON_INTERACTIVE。2、函数的参数格式有问题。a、比如public static extern int LogonUser(String lpszUserName, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, ref IntPtr phToken);中的lpszUserName、lpszDomain、lpszPassword就要写清楚。我就在这遇到过问题，第一次测试时，远程服务器就是一台独立的文件服务器，这是我的调用方式：LogonUser("myname", "192.168.1.48", "password", LOGON32_LOGON_NEW_CREDENTIALS, LOGON32_PROVIDER_DEFAULT, ref