Windows Mobile中如何建立GPRS连接以便Socket能正常通信(转帖)

手机开通GPRS以后，我们的socket 程序还不能直接建立网络连接，需要用连接管理器来获取当前可用连接，并自动选择一个最佳的连接途径，然后启用这个连接，在连接启动成功以后再用socket 进行网络连接方可正常进行。大概GPRS拨号和连接过程就是在这里自动进行的吧。源代码中封装了一个连接管理的类和测试代码，可以清楚地看到Windows Mobile 在socket 编程之前到底需要做什么样的操作。

首先需要枚举当前可用的连接

void CConnectManager::EnumNetIdentifier (OUT CStringArray &StrAry )

{

      CONNMGR_DESTINATION_INFO networkDestInfo = {0};

       // 得到网络列表

       for (DWORD dwEnumIndex=0; ; dwEnumIndex++ )

       {

             memset ( &networkDestInfo, 0, sizeof(CONNMGR_DESTINATION_INFO) );

             if ( ConnMgrEnumDestinations ( dwEnumIndex, &networkDestInfo ) == E_FAIL )

             {

                    break;

             }

             StrAry.Add ( networkDestInfo.szDescription );

       }

}

接下来找到“Internet”这个连接，可用远程URL映射的方式来完成，这样可以让系统自动选取一个最好的连接。

int CConnectManager::MapURLAndGUID (LPCTSTR lpszURL, OUT GUID &guidNetworkObject, OUT CString *pcsDesc/*=NULL*/)

{

       if (!lpszURL || lstrlen(lpszURL) < 1 )

             return FALSE;

       memset ( &guidNetworkObject, 0,sizeof(GUID) );

       intnIndex = 0;

      HRESULT hResult = ConnMgrMapURL ( lpszURL, &guidNetworkObject,(DWORD*)&nIndex );

       if (FAILED(hResult) )

       {

             nIndex = -1;

             DWORD dwLastError = GetLastError ();

             AfxMessageBox ( _T("Could not map a request to a network identifier"));

       }

       else

       {

             if ( pcsDesc )

             {

                    CONNMGR_DESTINATION_INFO DestInfo = {0};

                    if ( SUCCEEDED(ConnMgrEnumDestinations(nIndex, &DestInfo)) )

                    {

                           *pcsDesc = DestInfo.szDescription;

                    }

             }

       }

       return nIndex;

}

以下代码是用来启用指定编号的连接

BOOL CConnectManager::EstablishConnection (DWORD dwIndex )

{

      ReleaseConnection ();

       // 得到正确的连接信息

      CONNMGR_DESTINATION_INFO DestInfo = {0};

      HRESULT hResult = ConnMgrEnumDestinations(dwIndex, &DestInfo);

       BOOLbRet = FALSE;

      if(SUCCEEDED(hResult))

       {

             // 初始化连接结构

             CONNMGR_CONNECTIONINFO ConnInfo;

             ZeroMemory(&ConnInfo, sizeof(ConnInfo));

             ConnInfo.cbSize = sizeof(ConnInfo);

             ConnInfo.dwParams = CONNMGR_PARAM_GUIDDESTNET;

             ConnInfo.dwFlags = CONNMGR_FLAG_PROXY_HTTP | CONNMGR_FLAG_PROXY_WAP |CONNMGR_FLAG_PROXY_SOCKS4 | CONNMGR_FLAG_PROXY_SOCKS5;

             ConnInfo.dwPriority = CONNMGR_PRIORITY_USERINTERACTIVE;

             ConnInfo.guidDestNet = DestInfo.guid;

             ConnInfo.bExclusive     = FALSE;

             ConnInfo.bDisabled = FALSE;

             DWORD dwStatus = 0;

             hResult = ConnMgrEstablishConnectionSync(&ConnInfo, &m_hConnection,10*1000, &dwStatus );

             if(FAILED(hResult))

             {

                    m_hConnection = NULL;

             }

             else bRet = TRUE;

       }

       return bRet;

}

为了确保连接是否真正可用，需要检测连接状态，在规定的时间内如果未取得“连接成功”的状态，则认为连接未能正常启用，可能需要配置手机的连接管理器界面

BOOL CConnectManager::WaitForConnected (int nTimeoutSec, DWORD *pdwStatus/*=NULL*/ )

{

       DWORDdwStartTime = GetTickCount ();

       BOOLbRet = FALSE;

       while( GetTickCount ()-dwStartTime < (DWORD)nTimeoutSec * 1000 )

       {

             if ( m_hConnection )

             {

                    DWORD dwStatus = 0;

                    HRESULT hr = ConnMgrConnectionStatus ( m_hConnection, &dwStatus );

                    if ( pdwStatus ) *pdwStatus = dwStatus;

                    if ( SUCCEEDED(hr) )

                    {

                           if ( dwStatus == CONNMGR_STATUS_CONNECTED )

                           {

                                  bRet = TRUE;

                                  break;

                           }

                    }

             }

             Sleep ( 100 );

       }

       return bRet;

}

至此，我们的连接启用工作已经做完了，我们可以用我们熟悉的 socket 来编写网络通信程序了。下面是一个测试 socket 测试网络连接是否能正常建立的例子：

SetWaitCursor ();

CSocket sock;

sock.Create ();

if ( sock.Connect ( _T("www.baidu.com"), 80 ) )

{

      RestoreCursor ();

      AfxMessageBox ( _T("Connect to www.baidu.comsuccessfully"), MB_ICONINFORMATION );

}

else

{

      RestoreCursor ();

       AfxMessageBox( _T("Connect to www.baidu.comfailed") );

}