/// <summary>
/// Echo the message back to the peer
/// </summary>
/// <param name="peer">The remote peer object</param>
/// <param name="eventArguments">The received message event arguments</param>
async void EchoMessage(RemotePeer peer, DatagramSocketMessageReceivedEventArgs eventArguments)
{
if (!peer.IsMatching(eventArguments.RemoteAddress, eventArguments.RemotePort))
{
// In the sample we are communicating with just one peer. To communicate with multiple peers
// application should cache output streams (i.e. by using a hash map), because creating an output
// stream for each received datagram is costly. Keep in mind though, that every cache requires logic
// to remove old or unused elements; otherwise cache turns into a memory leaking structure.
NotifyUserFromAsyncThread(
String.Format(
"Got datagram from {0}:{1}, but already 'connected' to {2}",
eventArguments.RemoteAddress,
eventArguments.RemotePort,
peer),
NotifyType.ErrorMessage);
}
try
{
await peer.OutputStream.WriteAsync(eventArguments.GetDataReader().DetachBuffer());
}
catch (Exception exception)
{
// If this is an unknown status it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
NotifyUserFromAsyncThread("Send failed with error: " + exception.Message, NotifyType.ErrorMessage);
}
}
/// <summary>
/// Message received handler
/// </summary>
/// <param name="socket">The socket object</param>
/// <param name="eventArguments">The datagram event information</param>
async void MessageReceived(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs eventArguments)
{
object outObj;
if (CoreApplication.Properties.TryGetValue("remotePeer", out outObj))
{
EchoMessage((RemotePeer)outObj, eventArguments);
return;
}
// We do not have an output stream yet so create one.
try
{
IOutputStream outputStream = await socket.GetOutputStreamAsync(
eventArguments.RemoteAddress,
eventArguments.RemotePort);
// It might happen that the OnMessage was invoked more than once before the GetOutputStreamAsync
// completed. In this case we will end up with multiple streams - make sure we have just one of it.
RemotePeer peer;
lock (this)
{
if (CoreApplication.Properties.TryGetValue("remotePeer", out outObj))
{
peer = (RemotePeer)outObj;
}
else
{
peer = new RemotePeer(outputStream, eventArguments.RemoteAddress, eventArguments.RemotePort);
CoreApplication.Properties.Add("remotePeer", peer);
}
}
EchoMessage(peer, eventArguments);
}
catch (Exception exception)
{
// If this is an unknown status it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
NotifyUserFromAsyncThread("Connect failed with error: " + exception.Message, NotifyType.ErrorMessage);
}
}
/// <summary>
/// Echo the message back to the peer
/// </summary>
/// <param name="peer">The remote peer object</param>
/// <param name="eventArguments">The received message event arguments</param>
async void EchoMessage(RemotePeer peer, DatagramSocketMessageReceivedEventArgs eventArguments)
{
if (!peer.IsMatching(eventArguments.RemoteAddress, eventArguments.RemotePort))
{
// In the sample we are communicating with just one peer. To communicate with multiple peers, an
// application should cache output streams (e.g., by using a hash map), because creating an output
// stream for each received datagram is costly. Keep in mind though, that every cache requires logic
// to remove old or unused elements; otherwise, the cache will turn into a memory leaking structure.
NotifyUserFromAsyncThread(
String.Format(
"Got datagram from {0}:{1}, but already 'connected' to {2}",
eventArguments.RemoteAddress,
eventArguments.RemotePort,
peer),
NotifyType.ErrorMessage);
}
try
{
await peer.OutputStream.WriteAsync(eventArguments.GetDataReader().DetachBuffer());
}
catch (Exception exception)
{
// If this is an unknown status it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
NotifyUserFromAsyncThread("Send failed with error: " + exception.Message, NotifyType.ErrorMessage);
}
}
/// <summary>
/// Message received handler
/// </summary>
/// <param name="socket">The socket object</param>
/// <param name="eventArguments">The datagram event information</param>
async void MessageReceived(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs eventArguments)
{
object outObj;
if (CoreApplication.Properties.TryGetValue("remotePeer", out outObj))
{
EchoMessage((RemotePeer)outObj, eventArguments);
return;
}
// We do not have an output stream yet so create one.
try
{
IOutputStream outputStream = await socket.GetOutputStreamAsync(
eventArguments.RemoteAddress,
eventArguments.RemotePort);
// It might happen that the OnMessage was invoked more than once before the GetOutputStreamAsync call
// completed. In this case we will end up with multiple streams - just keep one of them.
RemotePeer peer;
lock (this)
{
if (CoreApplication.Properties.TryGetValue("remotePeer", out outObj))
{
peer = (RemotePeer)outObj;
}
else
{
peer = new RemotePeer(outputStream, eventArguments.RemoteAddress, eventArguments.RemotePort);
CoreApplication.Properties.Add("remotePeer", peer);
}
}
EchoMessage(peer, eventArguments);
}
catch (Exception exception)
{
// If this is an unknown status it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
NotifyUserFromAsyncThread("Connect failed with error: " + exception.Message, NotifyType.ErrorMessage);
}
}
