C# 连接自动拨号与断开分析

C#的自动拨号和断开当前连接的代码网上很多，可是没有一个是真正自动的，就算我指明了对那个连接进行拨号，也只是弹出那个拨号连接的窗口，想要拨号还需要自己手动点击“拨号”按钮，才能开始拨号。 到网上找了很久，终于找到了解决方法。

 

现在把源码贴出来，给大家研究分析用。

 

拨号控制管理类：

using System; using System.Collections.Generic; using System.Text; using System.Timers; using System.Runtime.InteropServices; using Microsoft.Win32; namespace ConnectionDial { public class Ras { // Fields private bool bConnected; private ConnectionNotify ConnectNotify; private const int DNLEN = 15; private string EntryName; private const int ERROR_BUFFER_TOO_SMALL = 0x25b; private int hrasconn; public const int MAX_PATH = 260; public Timer NotifyTimer; private const int PWLEN = 0x100; private const string Ras_Authenticate = "正在验证用户名与密码."; public const string Ras_Connected = "成功连接到"; public const string Ras_Connecting = "正在连接"; private const string Ras_DialUping = "正在拨..."; public const string Ras_Disconnected = "连接中断."; private const string Ras_Dot = "..."; private const int RAS_MaxCallbackNumber = 0x80; private const int RAS_MaxDeviceName = 0x80; private const int RAS_MaxDeviceType = 0x10; public const int RAS_MaxEntryName = 0x100; private const int RAS_MaxPhoneNumber = 0x80; private const string Ras_OpenPort = "正在打开端口..."; private const string Ras_PortOpend = "端口已经打开."; private RASCONN[] Rasconn; private const int RASCS_DONE = 0x2000; private const int RASCS_PAUSED = 0x1000; private const int UNLEN = 0x100; // Methods public Ras() { } public Ras(ConnectionNotify ConnectionDelegate, double interval) { this.ConnectNotify = ConnectionDelegate; this.NotifyTimer = new Timer(interval); this.NotifyTimer.Elapsed += new ElapsedEventHandler(this.TimerEvent); this.Rasconn = new RASCONN[1]; this.Rasconn[0].dwSize = Marshal.SizeOf(this.Rasconn[0]); this.NotifyTimer.Start(); this.bConnected = false; } public bool CreateEntry(int hWnd, out string strError) { int nErrorValue = RasCreatePhonebookEntry(hWnd, null); if (nErrorValue == 0) { strError = null; return true; } strError = this.GetErrorString(nErrorValue); return false; } public bool DeleteEntry(string strEntryName, out string strError) { int nErrorValue = RasDeleteEntry(null, strEntryName); if (nErrorValue == 0) { strError = null; return true; } strError = this.GetErrorString(nErrorValue); return false; } public bool DialUp(string strEntryName, out string strError) { bool lpfPassword = false; RASDIALPARAMS structure = new RASDIALPARAMS(); structure.dwSize = Marshal.SizeOf(structure); structure.szEntryName = strEntryName; RasDialEvent lpvNotifier = new RasDialEvent(this.RasDialFunc); int nErrorValue = RasGetEntryDialParams(null, ref structure, ref lpfPassword); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); return false; } this.ConnectNotify("正在连接" + structure.szEntryName + "...", 1); this.EntryName = strEntryName; this.hrasconn = 0; nErrorValue = RasDial(0, null, ref structure, 0, lpvNotifier, ref this.hrasconn); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); this.ConnectNotify(strError, 3); return false; } this.ConnectNotify("正在打开端口...", 1); strError = null; return true; } public bool EditEntry(int hWnd, string strEntryName, out string strError) { int nErrorValue = RasEditPhonebookEntry(hWnd, null, strEntryName); if (nErrorValue == 0) { strError = null; return true; } strError = this.GetErrorString(nErrorValue); return false; } public bool GetDefaultEntry(out string strEntry, out string strError) { RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE/Microsoft/RAS AutoDial/Default"); if (key != null) { string str = (string)key.GetValue("DefaultInternet"); if ((str != null) && (str.Length > 0)) { strEntry = str; strError = null; return true; } } strEntry = null; strError = "注册表访问失败."; return false; } public bool GetEntries(out string[] strEntryName, out string strError) { RASENTRYNAME[] lprasentryname = new RASENTRYNAME[1]; lprasentryname[0].dwSize = Marshal.SizeOf(lprasentryname[0]); int lpcb = 0; int lpcEntries = 0; int nErrorValue = RasEnumEntries(null, null, lprasentryname, ref lpcb, ref lpcEntries); switch (nErrorValue) { case 0: break; case 0x25b: lprasentryname = new RASENTRYNAME[lpcEntries]; lprasentryname[0].dwSize = Marshal.SizeOf(lprasentryname[0]); break; default: strError = this.GetErrorString(nErrorValue); strEntryName = null; return false; } nErrorValue = RasEnumEntries(null, null, lprasentryname, ref lpcb, ref lpcEntries); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); strEntryName = null; return false; } strEntryName = new string[lpcEntries]; for (int i = 0; i < lpcEntries; i++) { strEntryName[i] = lprasentryname[i].szEntryName; } strError = null; return true; } public bool GetEntryParams(string strEntryName, out string strPhoneNumber, out string strUserName, out string strPassword, out bool bRememberPassword, out string strError) { bool lpfPassword = false; RASDIALPARAMS structure = new RASDIALPARAMS(); structure.dwSize = Marshal.SizeOf(structure); structure.szEntryName = strEntryName; int nErrorValue = RasGetEntryDialParams(null, ref structure, ref lpfPassword); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); strPhoneNumber = null; strUserName = null; strPassword = null; bRememberPassword = false; strError = null; return false; } strPhoneNumber = structure.szPhoneNumber; strUserName = structure.szUserName; if (lpfPassword) { strPassword = structure.szPassword; } else { strPassword = null; } bRememberPassword = lpfPassword; strError = null; return true; } internal string GetErrorString(int nErrorValue) { if ((nErrorValue >= 600) && (nErrorValue < 0x2f2)) { int cBufSize = 0x100; string lpszErrorString = new string(new char[cBufSize]); if (RasGetErrorString(nErrorValue, lpszErrorString, cBufSize) != 0) { lpszErrorString = null; } if ((lpszErrorString != null) && (lpszErrorString.Length > 0)) { return lpszErrorString; } } return null; } public bool HangUp(out string strError) { this.bConnected = false; if (this.hrasconn != 0) { int nErrorValue = RasHangUp(this.hrasconn); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); this.ConnectNotify(strError, 0); return false; } } foreach (RASCONN rasconn in this.Rasconn) { if (rasconn.hrasconn != 0) { int num2 = RasHangUp(rasconn.hrasconn); if (num2 != 0) { strError = this.GetErrorString(num2); this.ConnectNotify(strError, 0); return false; } } } strError = null; this.ConnectNotify("连接中断.", 0); return true; } [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasCreatePhonebookEntry(int hwnd, string lpszPhonebook); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasDeleteEntry(string lpszPhonebook, string lpszEntry); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasDial(int lpRasDialExtensions, string lpszPhonebook, ref RASDIALPARAMS lpRasDialParams, int dwNotifierType, RasDialEvent lpvNotifier, ref int lphRasConn); private void RasDialFunc(uint unMsg, RASCONNSTATE rasconnstate, int dwError) { if (dwError != 0) { this.ConnectNotify(this.GetErrorString(dwError), 3); this.bConnected = false; if (this.hrasconn != 0) { int nErrorValue = RasHangUp(this.hrasconn); if (nErrorValue == 0) { this.ConnectNotify("连接中断.", 0); } else { this.ConnectNotify(this.GetErrorString(nErrorValue), 0); } } } else { if (rasconnstate == RASCONNSTATE.RASCS_PortOpened) { this.ConnectNotify("端口已经打开.", 1); } if (rasconnstate == RASCONNSTATE.RASCS_ConnectDevice) { this.ConnectNotify("正在拨...", 1); } if (rasconnstate == RASCONNSTATE.RASCS_Authenticate) { this.ConnectNotify("正在验证用户名与密码.", 1); } if (rasconnstate == RASCONNSTATE.RASCS_Connected) { this.bConnected = true; this.ConnectNotify("成功连接到" + this.EntryName + '.', 2); } } } [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasEditPhonebookEntry(int hwnd, string lpszPhonebook, string lpszEntryName); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasEnumConnections([In, Out] RASCONN[] lprasconn, ref int lpcb, ref int lpcConnections); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasEnumEntries(string reserved, string lpszPhonebook, [In, Out] RASENTRYNAME[] lprasentryname, ref int lpcb, ref int lpcEntries); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasGetConnectStatus(int hrasconn, ref RASCONNSTATUS lprasconnstatus); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasGetEntryDialParams(string lpszPhonebook, ref RASDIALPARAMS lprasdialparams, ref bool lpfPassword); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasGetErrorString(int uErrorValue, string lpszErrorString, int cBufSize); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasHangUp(int hrasconn); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasRenameEntry(string lpszPhonebook, string lpszOldEntry, string lpszNewEntry); [DllImport("rasapi32.dll", CharSet = CharSet.Auto)] private static extern int RasSetEntryDialParams(string lpszPhonebook, ref RASDIALPARAMS lprasdialparams, bool fRemovePassword); public bool RenameEntry(string strOldEntry, string strNewEntry, out string strError) { int nErrorValue = RasRenameEntry(null, strOldEntry, strNewEntry); if (nErrorValue == 0) { strError = null; return true; } strError = this.GetErrorString(nErrorValue); return false; } public void SetDefaultEntry(string strEntry) { if ((strEntry != null) && (strEntry.Length > 0)) { RegistryKey key = Registry.LocalMachine.OpenSubKey(@"SOFTWARE/Microsoft/RAS AutoDial/Default", true); if (key == null) { key = Registry.LocalMachine.CreateSubKey(@"SOFTWARE/Microsoft/RAS AutoDial/Default"); } key.SetValue("DefaultInternet", strEntry); } } public bool SetEntryParams(string strEntryName, string strPhoneNumber, string strUserName, string strPassword, bool bRememberPassword, out string strError) { RASDIALPARAMS structure = new RASDIALPARAMS(); structure.dwSize = Marshal.SizeOf(structure); structure.szEntryName = strEntryName; structure.szPhoneNumber = strPhoneNumber; structure.szUserName = strUserName; structure.szPassword = strPassword; int nErrorValue = RasSetEntryDialParams(null, ref structure, !bRememberPassword); if (nErrorValue != 0) { strError = this.GetErrorString(nErrorValue); return false; } strError = null; return true; } private void TimerEvent(object sender, ElapsedEventArgs e) { RASCONNSTATUS structure = new RASCONNSTATUS(); int lpcb = 0; int lpcConnections = 0; structure.dwSize = Marshal.SizeOf(structure); int nErrorValue = RasEnumConnections(this.Rasconn, ref lpcb, ref lpcConnections); switch (nErrorValue) { case 0: break; case 0x25b: this.Rasconn = new RASCONN[lpcConnections]; lpcb = this.Rasconn[0].dwSize = Marshal.SizeOf(this.Rasconn[0]); nErrorValue = RasEnumConnections(this.Rasconn, ref lpcb, ref lpcConnections); break; default: this.ConnectNotify(this.GetErrorString(nErrorValue), 3); return; } if (nErrorValue != 0) { this.ConnectNotify(this.GetErrorString(nErrorValue), 3); } else if ((lpcConnections < 1) && this.bConnected) { this.bConnected = false; this.ConnectNotify("连接中断.", 0); } else { for (int i = 0; i < lpcConnections; i++) { nErrorValue = RasGetConnectStatus(this.Rasconn[i].hrasconn, ref structure); if (nErrorValue != 0) { this.ConnectNotify(this.GetErrorString(nErrorValue), 3); return; } if ((structure.rasconnstate == RASCONNSTATE.RASCS_Connected) && !this.bConnected) { this.bConnected = true; this.ConnectNotify("成功连接到" + this.Rasconn[i].szEntryName + '.', 2); } if ((structure.rasconnstate == RASCONNSTATE.RASCS_Disconnected) && this.bConnected) { this.bConnected = false; this.ConnectNotify("连接中断.", 0); } } } } // Nested Types public delegate void ConnectionNotify(string strNotify, int bConnect); [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] private struct RASCONN { internal int dwSize; internal int hrasconn; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x101)] internal string szEntryName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x11)] internal string szDeviceType; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x81)] internal string szDeviceName; } private enum RASCONNSTATE { RASCS_AllDevicesConnected = 4, RASCS_AuthAck = 12, RASCS_AuthCallback = 8, RASCS_AuthChangePassword = 9, RASCS_Authenticate = 5, RASCS_Authenticated = 14, RASCS_AuthLinkSpeed = 11, RASCS_AuthNotify = 6, RASCS_AuthProject = 10, RASCS_AuthRetry = 7, RASCS_CallbackSetByCaller = 0x1002, RASCS_ConnectDevice = 2, RASCS_Connected = 0x2000, RASCS_DeviceConnected = 3, RASCS_Disconnected = 0x2001, RASCS_Interactive = 0x1000, RASCS_OpenPort = 0, RASCS_PasswordExpired = 0x1003, RASCS_PortOpened = 1, RASCS_PrepareForCallback = 15, RASCS_Projected = 0x12, RASCS_ReAuthenticate = 13, RASCS_RetryAuthentication = 0x1001, RASCS_SubEntryConnected = 0x13, RASCS_SubEntryDisconnected = 20, RASCS_WaitForCallback = 0x11, RASCS_WaitForModemReset = 0x10 } [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] private struct RASCONNSTATUS { internal int dwSize; internal Ras.RASCONNSTATE rasconnstate; internal int dwError; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x11)] internal string szDeviceType; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x81)] internal string szDeviceName; } private delegate void RasDialEvent(uint unMsg, Ras.RASCONNSTATE rasconnstate, int dwError); [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] private struct RASDIALPARAMS { internal int dwSize; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x101)] internal string szEntryName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x81)] internal string szPhoneNumber; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x81)] internal string szCallbackNumber; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x101)] internal string szUserName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x101)] internal string szPassword; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x10)] internal string szDomain; } [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] private struct RASENTRYNAME { internal int dwSize; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x101)] internal string szEntryName; } } }

 

测试代码[部分]（界面部分请自己用VS拖出来）：

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using ConnectionDial; namespace DialUpTest { public partial class Form1 : Form { private Ras ras; public Form1() { InitializeComponent(); this.ras = new Ras(new Ras.ConnectionNotify(this.RasConnectNotify), 1000.0); } private void Form1_Load(object sender, EventArgs e) { string[] strs; string str; this.ras.GetEntries(out strs, out str); foreach(string s in strs){ comboBox1.Items.Add(s); } comboBox1.SelectedIndex = 0; showAttr(); } private void showAttr() { int index = comboBox1.SelectedIndex; if (index >= 0) { string str; string str2; string str3; string str4; bool flag; this.ras.GetEntryParams((string)comboBox1.SelectedItem, out str, out str2, out str3, out flag, out str4); this.textBox1.Text = str2; this.textBox2.Text = str3; } } private void btnConnect_Click(object sender, EventArgs e) { string str; ras.DialUp((string)comboBox1.SelectedItem,out str); } private void btnDisconnect_Click(object sender, EventArgs e) { string str; ras.HangUp(out str); } private void btnExit_Click(object sender, EventArgs e) { this.Close(); } private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { showAttr(); } public void RasConnectNotify(string strNotify, int Connect) { msgListBox.Items.Add(strNotify); } } }

 

可以看到，上面那个拨号管理类的功能非常强大，大家可以根据这个类进行与拨号有关的其他设置，比如属性修改，新建连接等。

 

附注：

    虽然文章贴了快一年了，拨号管理只是本人本科毕业设计中的一个模块。现在已经很少接触.net了，因为我现在的专业是嵌入式，不过如果需要，我乐意跟大家共同讨论。

    现在看到大家对这篇文章这么感兴趣，可能在做C#的网络应用开发的过程中，需要使用到诸如拨号连接管理等功能，我这里推荐一个非常优秀的第三方库 DotRas，这项工程是个.net版的windows RAS(remote access service)管理库，带源码、dll库及详细文档说明。

    大家可以上这里访问和下载：http://dotras.codeplex.com/ 

    祝大家学习开心，工作顺利~