WinCE 6.0, work with GPRS/WiFi (C#)

Question

Hello. I'm working on a project, which should connect to servers through wifi/gprs. Project is an application for Windows CE 6.0 device, I'm writing in Visual Studio 2008 on C#.

I have two severs to work with. To first I have to connect via wifi, second - via gprs. So I need to know, how can I change the method of connecting between wifi and gprs.

I found and tried this way: I turn on both wifi and gprs on my device. So I work via wifi because it has a higher priority. When I need to work via gprs, I turn off wifi (SetDevicePower function). But when I turn wifi on, it doesn't connect to my Preferred Network back.

Also I heard about the way to change priority between gprs/wifi in OS priority table programmatically, but i didn't found any information about how to do this.

I hope you can help me.

Answer 1

I think the ConnectionManager API can do what you want. It allows you to select from the available interfaces and establish a network connection using whichever one you want to use.

// Get the interface you want to connect with. This can
// be a programmatic choice or a user selection.
const CONNMGR_CONNECTION_DETAILED_STATUS* status = GetDesiredInterface();

CONNMGR_CONNECTIONINFO info = { 0 };
info.cbSize = sizeof( CONNMGR_CONNECTIONINFO );
info.dwParams = CONNMGR_PARAM_GUIDDESTNET;
info.dwPriority = CONNMGR_PRIORITY_USERINTERACTIVE;

// allow connection manager to use any proxy it needs to make the connection
info.dwFlags = CONNMGR_FLAG_PROXY_HTTP | 
               CONNMGR_FLAG_PROXY_SOCKS4 | 
               CONNMGR_FLAG_PROXY_SOCKS5 | 
               CONNMGR_FLAG_PROXY_WAP;

// Get the destination meta-network GUID for the adapter with the given name. If the
// adapter doesn't have a name, the description usually works. If the adapter is a proxy,
// be sure to set the correct reference type.
if( S_OK == ::ConnMgrMapConRef( 
    ( CM_CONNTYPE_PROXY == status->dwType ) ? ConRefType_PROXY : ConRefType_NAP, 
    ( NULL != status->szAdapterName ) ? status->szAdapterName : status->szDescription, 
    &info.guidDestNet ) )
{
    DWORD status = 0;
    HANDLE connection = NULL;
    
    // Establish the connection. hr will either be E_FAIL or S_OK. Extended error 
    // information is stored in the status variable.
    HRESULT hr = ::ConnMgrEstablishConnectionSync( &info, 
                                                   &connection, 
                                                   30000, 
                                                   &status );
    if( S_OK == hr )
    {
        // use the connection wisely, then release it when you are finished
        ::ConnMgrReleaseConnection( connection, 1 );
    }
}

see: http://www.codeproject.com/Articles/98020/Using-the-Connection-Manager

-PaulH