C#訪問遠端主機資源的方法
阿新 • • 發佈：2018-11-09
最近要實現訪問遠端主機的共享目錄中的一個檔案。遇到了許可權問題。google了一下，找到了幾種解決方法，記錄如下：
一、呼叫Net use命令
// 使用方法： //if (Connect("192.168.1.48", "使用者名稱", "密碼")) //{ // File.Copy(@"\\192.168.1.48\共享目錄\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、呼叫WNetAddConnection2、WNetAddConnection3或者NetUseAdd函式，進行磁碟對映。
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的格式一定要正確，否則可能出現錯誤 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類
由於WebClient類可以上傳下載檔案，並且支援以http:、https:和file:開頭的URI，所以可以用WebClient類來傳輸檔案。
新增System.Net名稱空間後使用如下程式碼
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) { // 如果網路很慢，而檔案又很大，這時可能有超時異常（Time out）。 } } 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) { // 如果網路很慢，而檔案又很大，這時可能有超時異常（Time out）。 } } 類似的還可以試試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、角色模擬
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())
{
// 這裡使用LOGON32_LOGON_NEW_CREDENTIALS來訪問遠端資源。
// 如果要（通過模擬使用者獲得許可權）實現伺服器程式，訪問本地授權資料庫可
// 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、比較
方法一通過呼叫Shell命令Net Use實現，有點笨拙。
方法二和方法一有些相似之處。對映遠端資源，然後訪問。
方法三由於會有超時異常出現，所以在網路速度快、傳輸小檔案時是可以的。
方法四通過身份模擬實現遠端資源訪問。一些伺服器程序就是通過這種方式執行的。這種方法也是我的最愛。
六、要注意的地方
關於這幾種方法，google後都可以找到一些文章。但是等到自己實際測試時，有時會出現各種小錯誤，
這些錯誤基本來源於兩方面：
1、函式的引數選擇有問題，和自己的環境不相符。
比如
public static extern int LogonUser(String lpszUserName,
String lpszDomain,
String lpszPassword,
int dwLogonType,
int dwLogonProvider,
ref IntPtr phToken);
中的dwLogonType，要訪問遠端資源就要用LOGON32_LOGON_NEW_CREDENTIALS，
要模擬本機使用者就要用LOGON32_LOGON_INTERACTIVE。
2、函式的引數格式有問題。
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就要寫清楚。
我就在這遇到過問題，第一次測試時，遠端伺服器就是一臺獨立的檔案伺服器，這是我的呼叫方式：
LogonUser(“myname”, “192.168.1.48”, “password”, LOGON32_LOGON_NEW_CREDENTIALS,
LOGON32_PROVIDER_DEFAULT, ref token);
第二次測試時，遠端伺服器是域MyDomain中的一個成員伺服器，提供檔案服務。這時程式碼就應該是：
LogonUser(“myname”, “MyDomain”, “password”, LOGON32_LOGON_NEW_CREDENTIALS,
LOGON32_PROVIDER_DEFAULT, ref token);
注意，程式碼中是MyDomain而不是IP地址。
再如：
參考上面程式碼
string remote = @"\\192.168.1.48\generals";
string local = @"P:";
string username = @"Domain\UserName";
string password = @"Password";
如果@"\192.168.1.48\generals"變成@"\192.168.1.48\generals\”就會出錯；
如果是域中的使用者，那麼把@"Domain\UserName"變成@"UserName"就會出錯。
//原文連結http://www.cnblogs.com/h2appy/archive/2008/05/21/1204277.html