用指定账号运行代码

需要调用Windows登陆函数，从AdvAPI32.dll里面导入3个函数LogonUser，DuplicateToken和CloseHandle。具体过程和代码一并写在下面：

从Dll导入3个Windows函数

1. [DllImport("advapi32.dll", SetLastError = true)]
2. private static extern bool LogonUser(string lpszUsername, string lpszDomain, string lpszPassword, int dwLogonType, int dwLogonProvider, out IntPtr phToken);
3. [DllImport("advapi32.dll", SetLastError = true)]
4. private static extern bool DuplicateToken(IntPtr ExistingTokenHandle, Int32 ImpersonationLevel, out IntPtr DuplicateTokenHandle);
5. [DllImport("advapi32.dll", SetLastError = true)]
6. private static extern bool CloseHandle(IntPtr hHandle);

定义一些枚举变量

定义Windows函数所需的枚举变量

1. public enum WindowsLogonType
2. {
3.     INTERACTIVE = 2,
4.     NETWORK = 3,
5.     BATCH = 4,
6.     SERVICE = 5,
7.     UNLOCK = 7,
8.     NETWORK_CLEARTEXT = 8,
9.     NEW_CREDENTIALS = 9
10. }
11.  
12. public enum ImpersonationLevel
13. {
14.     SecurityAnonymous,
15.     SecurityIdentification,
16.     SecurityImpersonation,
17.     SecurityDelegation
18. }
19.  
20. const Int32 LOGON32_PROVIDER_DEFAULT = 0;

开始登陆过程：

登陆过程代码

1. IntPtr hToken = IntPtr.Zero;
2. WindowsIdentity windowsIdentity;
3.  
4. if (LogonUser(username, domain, password, LOGON32_LOGON_SERVICE, LOGON32_PROVIDER_DEFAULT, out hToken))
5. {
6.     windowsIdentity = new WindowsIdentity(hToken);
7.     WindowsImpersonationContext impersonationContext = windowsIdentity.Impersonate();
8.     //Code here running with new credential
9.     impersonationContext.Undo();
10.     //exit new credential context, old credential become active.
11. }
12. else
13. {
14.     int ret = Marshal.GetLastWin32Error();
15.     Console.WriteLine("Logon as service failed, Error Code: " + ret.ToString());
16. }
17. if (hToken != IntPtr.Zero) CloseHandle(hToken);

Windows登陆后返回一个句柄，拿着这个句柄可以生成一个WindowsIdentity，然后WindowsIdentity的Impersonate函数会把当前账号入栈，新帐号激活，并且返回一个WindowsImpersonationContext。这时后面的代码就运行在新帐号权限下面，想返回之前的账号时用WindowsImpersonationContext的Undo函数就可以撤销账号的更改，旧帐号激活。