C#实现拨号上网

using System; using System.Runtime.InteropServices; namespace RAS { public class RasManager { public const int RAS_MaxEntryName = 256; public const int RAS_MaxPhoneNumber = 128; public const int UNLEN = 256; public const int PWLEN = 256; public const int DNLEN = 15; public const int MAX_PATH = 260; public const int RAS_MaxDeviceType = 16; public const int RAS_MaxCallbackNumber = RAS_MaxPhoneNumber; public delegate void Callback(uint unMsg, int rasconnstate, int dwError); [StructLayout(LayoutKind.Sequential, Pack=4, CharSet=CharSet.Auto)] public struct RASDIALPARAMS { public int dwSize; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=RAS_MaxEntryName + 1)] public string szEntryName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=RAS_MaxPhoneNumber + 1)] public string szPhoneNumber; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=RAS_MaxCallbackNumber+ 1)] public string szCallbackNumber; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=UNLEN + 1)] public string szUserName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=PWLEN + 1)] public string szPassword; [MarshalAs(UnmanagedType.ByValTStr, SizeConst=DNLEN + 1)] public string szDomain; public int dwSubEntry; public int dwCallbackId; } [DllImport("rasapi32.dll", CharSet=CharSet.Auto)] public static extern int RasDial (int lpRasDialExtensions, string lpszPhonebook, ref RASDIALPARAMS lprasdialparams, int dwNotifierType, Callback lpvNotifier, ref int lphRasConn); private RASDIALPARAMS RasDialParams; private int Connection; public RasManager() { Connection = 0; RasDialParams = new RASDIALPARAMS(); RasDialParams.dwSize = Marshal.SizeOf(RasDialParams); } #region Properties public string UserName { get { return RasDialParams.szUserName; } set { RasDialParams.szUserName = value; } } public string Password { get { return RasDialParams.szPassword; } set { RasDialParams.szPassword = value; } } public string EntryName { get { return RasDialParams.szEntryName; } set { RasDialParams.szEntryName = value; } } #endregion public int Connect() { Callback rasDialFunc = new Callback(RasManager.RasDialFunc); RasDialParams.szEntryName += "\0"; RasDialParams.szUserName += "\0"; RasDialParams.szPassword += "\0"; int result = RasDial (0, null, ref RasDialParams, 0, rasDialFunc, ref Connection); return result; } public static void RasDialFunc(uint unMsg, int rasconnstate, int dwError) { } } } An example of establishing a connection: RasManager myRas = new RasManager(); myRas.EntryName = "MyPhonebook entry"; // entry name in phonebook myRas.UserName = "username"; myRas.Password = "password"; myRas.Connect().ToString();