/// <summary>
/// Performs a search for UPnP devices on all active network interfaces.
/// </summary>
/// <param name="searchTarget">The search target. If this is null, a search
/// for all UPnP devices will be performed.</param>
/// <param name="timeout">The timespan after which to cancel the search
/// and return the results to the caller. If this is null, the method blocks
/// until the search has been completed.</param>
/// <returns>An enumerable collection of discovered UPnP devices.</returns>
/// <exception cref="InvalidOperationException">An error occurred while
/// performing an SSDP search-operation.</exception>
/// <remarks>
/// A full UPnP search can take 9 seconds or longer;
///
/// Possible values for the searchTarget parameter include:
/// * ssdp:all (searches for all devices and services)
/// * ssdp:rootdevice (searches for root devices only)
/// For details on all possible values for the searchTarget parameter, refer
/// to the 'UPnP Device Architecture 1.1' document, page 33.
/// </remarks>
static IEnumerable <UPnPDevice> FindDevices(string searchTarget = null,
TimeSpan?timeout = null)
{
UPnPDeviceFinder deviceFinder = new UPnPDeviceFinder();
DeviceFinderCallback dfCallback = new DeviceFinderCallback();
if (searchTarget == null)
{
searchTarget = "ssdp:all";
}
int findHandle = deviceFinder.CreateAsyncFind(searchTarget, 0, dfCallback);
if (findHandle == 0)
{
throw new InvalidOperationException("Asynchronous search operation could " +
"not be created.");
}
// Start the asynchronous search.
deviceFinder.StartAsyncFind(findHandle);
if (timeout == null)
{
timeout = TimeSpan.FromMilliseconds(-1);
}
// Wait until the search has been completed or the specified timeout has
// expired.
if (!dfCallback.SearchCompleted.WaitOne(timeout.Value))
{
deviceFinder.CancelAsyncFind(findHandle);
}
// The Devices property of the DeviceFinderCallback contains the UPnP devices
// that were discovered.
return(dfCallback.Devices);
}
/// <summary>
/// Stops the current asynchronous search.
/// </summary>
public void Stop()
{
if (Logging.Enabled)
{
Logging.Log(
this,
string.Format(
"Async discovery stopping with - SearchURI:'{0}', ResolveNetworkInterface:'{1}', AddressFamily:'{2}'",
msSearchURI, mbResolveNetworkInterface, mafAddressFamily.ToString()), 1);
}
try
{
// If we are searching
if (miFindHandle != 0)
{
// Cancel the search
if (Logging.Enabled)
{
Logging.Log(this, "Cancelling async find");
}
mfFinder.CancelAsyncFind(miFindHandle);
// Ignore the callback
if (Logging.Enabled)
{
Logging.Log(this, "Notifying callback to ignore");
}
mdfcCallback.Ignore();
// Clear the callback
mdfcCallback = null;
// Reset the find handle
miFindHandle = 0;
}
}
finally
{
if (Logging.Enabled)
{
Logging.Log(this, "Finished async discovery stop", -1);
}
}
}
//method to stop asynchronous search
public void StopSearchingForDevices()
{
DeviceFinder.CancelAsyncFind(MediaServers);
}
