/// <summary>
/// Receive method to handle the camera responses.
/// </summary>
/// <param name="ar">The async result.</param>
private void ListeningReceive(IAsyncResult ar)
{
IPEndPoint source = null;
byte[] bytes = null;
lock (listeningClientLock)
{
// check so client is still active
if (listeningClient == null)
{
return;
}
// receive the bytes from the source
source = new IPEndPoint(IPAddress.Any, MULTICAST_PORT);
bytes = listeningClient.EndReceive(ar, ref source);
// continue to listen for more packets
listeningClient.BeginReceive(ListeningReceive, new object());
}
try
{
// convert the response to readable text
string response = Encoding.UTF8.GetString(bytes);
using (StringReader responseReader = new StringReader(response))
{
// parse the xml soap message to a discovery response
XmlSerializer serializer = new XmlSerializer(typeof(DiscoveryResponse));
DiscoveryResponse discoveryMessage = (DiscoveryResponse)serializer.Deserialize(XmlReader.Create(responseReader));
// validate response guid in the response, so it corresponds to the guid we sent with the discovery request
Guid responseID;
if (Guid.TryParse(discoveryMessage.Header.RelatesTo.Substring(5), out responseID) && responseID == messageGuid)
{
// get the main soap service url for the camera
string deviceServiceURL = discoveryMessage.Body.ProbeMatches.ProbeMatch.XAddrs;
// get the properties about the camera
string[] properties = discoveryMessage.Body.ProbeMatches.ProbeMatch.Scopes.Split(' ');
string name = properties.First(p => p.StartsWith("onvif://www.onvif.org/name/")).Substring("onvif://www.onvif.org/name/".Length);
string model = properties.First(p => p.StartsWith("onvif://www.onvif.org/model/")).Substring("onvif://www.onvif.org/model/".Length);
string location = properties.First(p => p.StartsWith("onvif://www.onvif.org/location/")).Substring("onvif://www.onvif.org/location/".Length);
// create a new "camera" instance and trigger event that it is found
var camera = new DiscoveredCamera(name, model, source.Address, location, deviceServiceURL);
CameraDiscovered.Trigger(this, new CameraDiscoveredEventArgs(camera));
// add the camera to the local list
discoveredCameras.Add(camera);
}
}
}
catch { /* Probably just an invalid response, nothing to do here */ }
}
protected void OnDiscovered(TargetDevice device)
{
CameraDiscovered?.Invoke(this, new CameraDeviceEventArgs {
CameraDevice = device
});
}
