Home > Article > Backend Development > Sharing multiple methods of accessing remote host resources in C#
Sharing multiple methods of accessing remote host resources in C#
- Y2JOriginal
- 2017-04-25 09:55:422327browse
最近要实现访问远程主机的共享目录中的一个文件。遇到了权限问题。google了一下，找到了几种解决方法，记录如下：
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（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) { // 如果网络很慢，而文件又很大，这时可能有超时异常（Time out）。 } }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
/// <summary>
/// 身份模拟实现远程资源访问
/// </summary>
public class FileImpersonation
{
// 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;
/// <summary>
/// 身份模拟
/// </summary>
/// <param name="userName">独立服务器用IP，域环境就用域名</param>
/// <param name="domain"></param>
/// <param name="password"></param>
/// <returns></returns>
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)
{
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;
}
/// <summary>
/// 取消模拟身份
/// </summary>
public void undoImpersonation()
{
impersonationContext.Undo();
}
/// <summary>
///
/// </summary>
/// <param name="domain">独立服务器用IP，域环境就用域名</param>
/// <param name="username"></param>
/// <param name="password"></param>
/// <param name="act">需要执行的操作</param>
public void ImpersonateFunc(string username, string domain, string password, Action act)
{
bool isImpersonated = false;
try
{
if (impersonateValidUser(username, domain, password))
{
isImpersonated = true;
//File.Copy(@"\\192.168.1.48\generals\now.htm", "c:\\now.htm", true);
act();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
if (isImpersonated)
undoImpersonation();
}
}
//
}
FileImpersonation imp = new FileImpersonation();
imp.ImpersonateFunc("Administrator", "192.168.0.125", "xxxx", () =>
{
var source = new DirectoryInfo(@"D:\HR");
string targetFolder = @"\\192.168.0.125\d$\HR";
if (!Directory.Exists(targetFolder))
{
Directory.CreateDirectory(targetFolder);
}
foreach (FileInfo item in source.GetFiles())
{
string targertFile = Path.Combine(targetFolder, item.Name);
File.Copy(item.FullName, targertFile, true);
}
});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 token);
第二次测试时，远程服务器是域MyDomain中的一个成员服务器，提供文件服务。这时代码就应该是：
LogonUser("myname", "MyDomain", "password", LOGON32_LOGON_NEW_CREDENTIALS,
LOGON32_PROVIDER_DEFAULT, ref token); 注意，代码中是MyDomain而不是IP地址。
b、再如：
参考上面代码
string remote = @"\\192.168.1.48\generals";
string local = @"P:";
string username = @"Domain\UserName";
string password = @"Password"; 如果@"\\192.168.1.48\generals"变成@"\\192.168.1.48\generals\”就会出错；
如果是域中的用户，那么把@"Domain\UserName"变成@"UserName"就会出错。
The above is the detailed content of Sharing multiple methods of accessing remote host resources in C#. For more information, please follow other related articles on the PHP Chinese website!
Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn