/// <summary>
/// Returns a list of servers that support the specified specification.
/// </summary>
/// <param name="specification">Unique identifier for one OPC specification.</param>
/// <param name="discoveryServerUrl">The URL of the discovery server to be used.</param>
/// <param name="identity">The user identity to use when discovering the servers.</param>
/// <returns>Returns a list of found OPC servers.</returns>
public static List <OpcServer> GetServers(OpcSpecification specification, string discoveryServerUrl, OpcUserIdentity identity)
{
List <OpcServer> serverList = new List <OpcServer>();
bool dcomDiscovery = false;
if (specification == OpcSpecification.OPC_AE_10)
{
dcomDiscovery = true;
}
if (specification == OpcSpecification.OPC_DA_20 ||
specification == OpcSpecification.OPC_DA_30)
{
dcomDiscovery = true;
}
if (specification == OpcSpecification.OPC_HDA_10)
{
dcomDiscovery = true;
}
if (specification == null)
{
return(serverList);
}
else if (dcomDiscovery)
{
if (_discovery == null || _hostName != discoveryServerUrl)
{
if (_discovery != null)
{
_discovery.Dispose();
}
_hostName = discoveryServerUrl;
_discovery = new Technosoftware.DaAeHdaClient.Com.ServerEnumerator();
}
OpcServer[] servers = _discovery.GetAvailableServers(specification);
if (servers != null)
{
foreach (OpcServer server in servers)
{
serverList.Add(server);
}
}
}
return(serverList);
}
/// <summary>
/// Connects to the specified COM server.
/// </summary>
public static object Connect(OpcUrl url, OpcConnectData connectData)
{
// parse path to find prog id and clsid.
string progID = url.Path;
string clsid = null;
int index = url.Path.IndexOf('/');
if (index >= 0)
{
progID = url.Path.Substring(0, index);
clsid = url.Path.Substring(index + 1);
}
// look up prog id if clsid not specified in the url.
Guid guid;
if (clsid == null)
{
// use OpcEnum to lookup the prog id.
guid = new ServerEnumerator().CLSIDFromProgID(progID, url.HostName, connectData);
// check if prog id is actually a clsid string.
if (guid == Guid.Empty)
{
try
{
guid = new Guid(progID);
}
catch
{
throw new OpcResultException(new OpcResult((int)OpcResult.CO_E_CLASSSTRING.Code, OpcResult.FuncCallType.SysFuncCall, null), String.Format("Could not connect to server {0}", progID));
}
}
}
// convert clsid string to a guid.
else
{
try
{
guid = new Guid(clsid);
}
catch
{
throw new OpcResultException(new OpcResult((int)OpcResult.CO_E_CLASSSTRING.Code, OpcResult.FuncCallType.SysFuncCall, null), String.Format("Could not connect to server {0}", progID));
}
}
// get the credentials.
OpcUserIdentity credentials = (connectData != null) ? connectData.UserIdentity : null;
// instantiate the server using CoCreateInstanceEx.
if (connectData == null || connectData.LicenseKey == null)
{
try
{
return(Utilities.Interop.CreateInstance(guid, url.HostName, credentials));
}
catch (Exception e)
{
throw new OpcResultException(OpcResult.CO_E_CLASSSTRING, e.Message, e);
}
}
// instantiate the server using IClassFactory2.
else
{
try
{
return(null);
//return Technosoftware.DaAeHdaClient.Utilities.Interop.CreateInstanceWithLicenseKey(guid, url.HostName, credentials, connectData.LicenseKey);
}
catch (Exception e)
{
throw new OpcResultException(OpcResult.CO_E_CLASSSTRING, e.Message, e);
}
}
}
