I have no trouble using a UDPClient's BeginReceive method from a console application. However, I am not able to get this to run from my WPF app. I'm very confused. I am assuming that it has something to do with where I am calling this code from. I am new to WPF. Is there something I'm misunderstanding about UDPClient's binding in WPF?
Does Inheriting from Application so something that could interfere with UDPClient BeginReceive()
Now this code call stack goes from App.xaml.cs, to ButtonClick(), that creates an instance of MachineItem and calls StartMachine. No weird threading or anything going on (unless WPF does something I'm not aware of during a button click). Again, BeginReceive() is called, but if I put a breakpoint in Receive(IAsyncResult res), nothing ever happens.
public partial class App : Application
{
//... all the normal stuff here
private void Button_Click(object sender, RoutedEventArgs e)
{
MachineItem currentMachine = (MachineItem)(sender as Button).DataContext;
currentMachine.StartMachine();
}
}
Now after button click, this happens:
public class MachineItem : INotifyPropertyChanged
{
IPEndPoint sendersEndPoint;
UdpClient listener;
public void StartMachine()
{
listener = new UdpClient
{
ExclusiveAddressUse = false
};
listener.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
IPAddress ip = System.Net.IPAddress.Parse(this.LocalNIC_IPAddress);
int ipInt = BitConverter.ToInt32(ip.GetAddressBytes(), 0);
IPEndPoint endPoint = new IPEndPoint(ipInt, 60811); //new IPEndPoint(IPAddress.Any, listenPort); this might allow me not to know the IP of this local device!
listener.Client.Bind(endPoint);
listener.BeginReceive(new AsyncCallback(Receive), null);
Thread.Sleep(20000); // this is just for testing purposes
}
private void Receive(IAsyncResult res)
{
byte[] bytes = listener.EndReceive(res, ref sendersEndPoint);
listener.BeginReceive(new AsyncCallback(Receive), null);
Console.WriteLine("Received");
}
}
Update: I tried putting this UDP code where the application first starts to further narrow down the problem. I'm still getting the exact same behavior- the Client is able to call BeginReceive(), but then nothing happens even when UDP packets come in, in other words, the async method Receive() is never called...
public partial class WVGUIApp : Application
{
IPEndPoint sendersEndPoint;
UdpClient listener;
void AppStartup(object sender, StartupEventArgs args)
{
LoadMachineData();
MainWindow mainWindow = new MainWindow();
mainWindow.Show();
listener = new UdpClient
{
ExclusiveAddressUse = false
};
listener.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
IPAddress ip = System.Net.IPAddress.Parse("10.178.100.111");
int ipInt = BitConverter.ToInt32(ip.GetAddressBytes(), 0);
IPEndPoint endPoint = new IPEndPoint(ipInt, 60811); //new IPEndPoint(IPAddress.Any, listenPort); this might allow me not to know the IP of this local device!
listener.Client.Bind(endPoint);
listener.BeginReceive(new AsyncCallback(Receive), null);
//Thread.Sleep(20000);
}
private void Receive(IAsyncResult res)
{
byte[] bytes = listener.EndReceive(res, ref sendersEndPoint);
listener.BeginReceive(new AsyncCallback(Receive), null);
Console.WriteLine("Received");
}
}
