I got two Windows UWP Apps. One of them (the "server") is running on a Raspberry Pi 2 on Windows IoT (10586.0). The other (the "client") is running on any Windows 10 device within the same network.
What I want is to get the apps to "talk" to each other. For the moment I just want to send simple String from the client to the server. Later on, serialized data should be transferred trough the network.
This is the code for the server App:
namespace LCARSHomeAutomation
{
/// <summary>
/// Eine leere Seite, die eigenständig verwendet oder zu der innerhalb eines Rahmens navigiert werden kann.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
try {
EstablishNetworking();
txb_Events.Text += "Server Running";
}catch (Exception ex)
{
txb_Events.Text += ex.Message;
}
}
private async void EstablishNetworking()
{
await StartListener();
}
public async Task StartListener()
{
StreamSocketListener listener = new StreamSocketListener();
listener.ConnectionReceived += OnConnection;
listener.Control.KeepAlive = true;
try
{
await listener.BindServiceNameAsync("5463");
}
catch (Exception ex)
{
if (SocketError.GetStatus(ex.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
//Logs.Add(ex.Message);
txb_Events.Text += ex.Message;
}
}
private async void OnConnection(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
{
Stream inStream = args.Socket.InputStream.AsStreamForRead();
StreamReader reader = new StreamReader(inStream);
string request = await reader.ReadLineAsync();
await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() =>
{
// Your UI update code goes here!
txb_Events.Text += (String)request;
});
}
private async Task ConnectSocket()
{
StreamSocket socket = new StreamSocket();
socket.Control.KeepAlive = false;
HostName host = new HostName("localhost");
try
{
await socket.ConnectAsync(host, "5463");
Stream streamOut = socket.OutputStream.AsStreamForWrite();
StreamWriter writer = new StreamWriter(streamOut);
string request = "Test Self App \n";
await writer.WriteLineAsync(request);
await writer.FlushAsync();
socket.Dispose();
}
catch (Exception ex)
{
txb_Events.Text += ex.Message;
//Logs.Add(ex.Message)
}
}
private async void btn_Send_Click(object sender, RoutedEventArgs e)
{
await ConnectSocket();
}
}
}
As you can see, I'm establishing a network connection with the same app on the same host and send the string "Test Self App". This works fine for quite some time but after a while I get the Error:
Exception thrown: 'System.Runtime.InteropServices.COMException' in mscorlib.ni.dll
WinRT information: No connection could be made because the target machine actively refused it.
So, this is my first question: What is this Error and how can I fix this?
The other thing is: I'm not able to establish a network Connection between the server and the Client. I don't know, what I am doing wrong. This is the code of the "Client":
namespace LCARSRemote
{
/// <summary>
/// Eine leere Seite, die eigenständig verwendet oder zu der innerhalb eines Rahmens navigiert werden kann.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}
private async void btn_Send_Click(object sender, RoutedEventArgs e)
{
StreamSocket socket = new StreamSocket();
HostName host = new HostName("localhost"); //Replace with coorect hostname when running on RPi
try
{
try {
await socket.ConnectAsync(host, "5463");
}
catch(Exception ex)
{
txb_Events.Text += ex.Message;
}
Stream streamOut = socket.OutputStream.AsStreamForWrite();
StreamWriter writer = new StreamWriter(streamOut);
string request = "Remote App Test";
await writer.WriteLineAsync(request);
await writer.FlushAsync();
socket.Dispose();
}
catch (Exception ex)
{
txb_Events.Text += ex.Message;
//Logs.Add(ex.Message)
}
}
}
}
When I click on the btn_Send, I get the error message
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
and
A method was called at an unexpected time. (Exception from HRESULT: 0x8000000E)
What am I doing wrong? Maybe I should say, that I'm relatively new in programming network connections, sockets etc.
Thanks for any help!
