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Problems with receiving UDP messages in Metro-Apps

I'm currently working on a project and one of the featured devices is a Windows Tablet. To "connect" it to other devices (like some Raspberry Pi) in the project environment UDP is used to send messages. The Windows Tablet is intended to be some controlling device with soem touch functionality. Therefore I'm writing an App (and the intention of the App is not to put it into the Windows Store). The UDP part in this work is quite painful because I had to do much research since I started with no experience in App programming. More painful than the programming is, that I practically finished the work only to start over again because the App didn't receive UDP anymore.
Here's my code (I removed elements not relevant to the actual problem). I apologize for the bad coding....
App.xaml.cs:
sealed partial class App : Application
{
NetworkInterface ni = new NetworkInterface();
public App()
{
this.InitializeComponent();
this.Suspending += OnSuspending;
ni.MessageReceived += OnMessageReceived;
ni.Connect(new HostName("127.0.0.1"), "5556");
}
private void OnMessageReceived(object sender, MessageReceivedEventArgs e)
{
Debug.WriteLine("Processing");
Debug.WriteLine(e.Message.Data);
}
public static new App Current
{
get { return Application.Current as App; }
}
private DatagramSocket _socket;
protected override void OnLaunched(LaunchActivatedEventArgs e)
{
Update_Timer();
}
DispatcherTimer timer = new DispatcherTimer();
private void Update_Timer()
{
timer.Start();
timer.Interval = new TimeSpan(0,0,0,0,500);
timer.Tick += alive;
}
private void alive(object sender, object e)
{
if (start == 0) {
Debug.WriteLine("App-Startup");
ni.SendMessage("Startup...");
start++;
}
else
{
Debug.WriteLine("App-Alive");
ni.SendMessage("alive");
start++;
}
}
}
This part of code is to send and receive Messages in the backgrond in the whole App.
And a NetworkInterface class:
class NetworkInterface
{
private DatagramSocket _socket;
public bool IsConnected { get; set; }
public NetworkInterface()
{
IsConnected = false;
_socket = new DatagramSocket();
_socket.MessageReceived += OnSocketMessageReceived;
}
public async void Connect(HostName remoteHostName, string remoteServiceNameOrPort)
{
if (IsConnected != true)
{
await _socket.BindServiceNameAsync("5321");
await _socket.ConnectAsync(remoteHostName, remoteServiceNameOrPort);
}
IsConnected = true;
}
public void alive(object sender, object e)
{
Debug.WriteLine("alive");
}
public event EventHandler<MessageReceivedEventArgs> MessageReceived;
private void OnSocketMessageReceived(DatagramSocket sender, DatagramSocketMessageReceivedEventArgs args)
{
var reader = args.GetDataReader();
var count = reader.UnconsumedBufferLength;
var data = reader.ReadString(count);
Debug.WriteLine(args);
if (MessageReceived != null)
{
var ea = new MessageReceivedEventArgs();
ea.Message = new Message() { Data = data };
ea.RemoteHostName = args.RemoteAddress;
ea.RemotePort = args.RemotePort;
MessageReceived(this, ea);
}
}
DataWriter _writer = null;
public async void SendMessage(string message)
{
if (_writer == null)
{
var stream = _socket.OutputStream;
_writer = new DataWriter(stream);
}
_writer.WriteString(message);
await _writer.StoreAsync();
}
}
The main problems are:
If I dont send something before receiving, I won't be able top get an message.
If I send before I have random Faults at this line:
var reader = args.GetDataReader();
If nothing fails, I'm not able to receive messages from a local Python script (which works) but I can send messages from a local program which the App receives.
Does anyone know how I can fix these problems?
Thanks in advance!

Raising Custom Class Events In Windows Service C#

I did write a windows service that can connect to a network device using a dll. so everything works fine, but The event handler does not work in win service! here is my code :
My Custom Class Code :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace MyNewService
{
public class zkemkeeperHandler
{
public event EventHandler OnFinger;
public event EventHandler<VerifyEventArgs> OnVerify;
private System.Diagnostics.EventLog eventLog1 = new System.Diagnostics.EventLog();
public zkemkeeper.CZKEMClass axCZKEM1 = new zkemkeeper.CZKEMClass();
private bool bIsConnected = false;
private int iMachineNumber = 1;
public zkemkeeperHandler()
{
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).BeginInit();
this.eventLog1.Log = "DoDyLog";
this.eventLog1.Source = "DoDyLogSource";
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).EndInit();
eventLog1.WriteEntry("zkemkeeperHandler constructor");
}
public void startService()
{
eventLog1.WriteEntry("start service for (192.168.0.77:4370)");
bIsConnected = axCZKEM1.Connect_Net("192.168.0.77", Convert.ToInt32("4370"));
if (bIsConnected == true)
{
eventLog1.WriteEntry("bIsConnected == true !");
iMachineNumber = 1;
if (axCZKEM1.RegEvent(iMachineNumber, 65535))
{
this.axCZKEM1.OnFinger += new kemkeeper._IZKEMEvents_OnFingerEventHandler(axCZKEM1_OnFinger);
this.axCZKEM1.OnVerify += new zkemkeeper._IZKEMEvents_OnVerifyEventHandler(axCZKEM1_OnVerify);
//This Log Appears in Event Viewer
eventLog1.WriteEntry("Define events (OnFingers and OnVerify) !");
//This Line Fires Event in Service1.cs for testing event handler
Finger(EventArgs.Empty);
}
}
else
{
eventLog1.WriteEntry("Unable to connect the device");
}
}
public void stopService()
{
if (bIsConnected) {axCZKEM1.Disconnect(); bIsConnected = false;}
}
//This method doesn't run :(
private void axCZKEM1_OnFinger()
{
Finger(EventArgs.Empty);
}
//This method doesn't run too :(
private void axCZKEM1_OnVerify(int iUserID)
{
VerifyEventArgs args = new VerifyEventArgs();
args.UserID = iUserID;
Verify(args);
}
public class VerifyEventArgs : EventArgs
{
public int UserID { get; set; }
}
protected virtual void Finger(EventArgs e)
{
EventHandler handler = OnFinger;
if (handler != null)
handler(this, e);
}
protected virtual void Verify(VerifyEventArgs e)
{
EventHandler<VerifyEventArgs> handler = OnVerify;
if (handler != null)
handler(this, e);
}
}
}
My Main Service Class Code :
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;
using System.Linq;
using System.Threading;
namespace MyNewService
{
public class Service1 : System.ServiceProcess.ServiceBase
{
private System.Diagnostics.EventLog eventLog1;
private System.ComponentModel.Container components = null;
zkemkeeperHandler zkh;
public Service1()
{
InitializeComponent();
if (!System.Diagnostics.EventLog.SourceExists("DoDyLogSource"))
{
System.Diagnostics.EventLog.CreateEventSource("DoDyLogSource", "DoDyLog");
}
eventLog1.Source = "DoDyLogSource";
eventLog1.Log = "DoDyLog";
eventLog1.WriteEntry("Preparing to start service");
try
{
startZKHandler();
}
catch (Exception ex)
{
eventLog1.WriteEntry(ex.InnerException.Message);
}
}
private void startZKHandler()
{
eventLog1.WriteEntry("creating zkemkeeper handler class");
zkh = new zkemkeeperHandler();
zkh.OnFinger += OnFinger;
zkh.OnVerify += OnVerify;
zkh.startService();
}
private void stopZKHandler()
{
eventLog1.WriteEntry("Disconnecting from device (192.168.0.77)...");
zkh.stopService();
}
private void writeLog2DB(string message)
{
try
{
eventLog1.WriteEntry("writing to database");
DB.DBase.LogTable.AddObject(new LogTable
{
ID = ++DB.IDCounter,
deviceLog = message
});
DB.DBase.SaveChanges();
}
catch (Exception ex)
{
eventLog1.WriteEntry(ex.Message + " - " + ex.InnerException.Message);
}
this.EventLog.Log = "Event Stored in DB.";
}
// The main entry point for the process
static void Main()
{
System.ServiceProcess.ServiceBase[] ServicesToRun;
ServicesToRun = new System.ServiceProcess.ServiceBase[] { new MyNewService.Service1()};
System.ServiceProcess.ServiceBase.Run(ServicesToRun);
}
private void InitializeComponent()
{
this.eventLog1 = new System.Diagnostics.EventLog();
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).BeginInit();
this.eventLog1.Log = "DoDyLog";
this.eventLog1.Source = "DoDyLogSource";
this.ServiceName = "MyNewService";
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).EndInit();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
protected override void OnStart(string[] args)
{
// TODO: Add code here to start your service.
eventLog1.WriteEntry("my service started");
}
protected override void OnStop()
{
// TODO: Add code here to perform any tear-down necessary to stop your service.
eventLog1.WriteEntry("my service stoped");
stopZKHandler();
}
protected override void OnContinue()
{
eventLog1.WriteEntry("my service is continuing in working");
}
private void OnFinger(object sender, EventArgs e)
{
eventLog1.WriteEntry("Finger Event Raised");
}
private void OnVerify(object sender, zkemkeeperHandler.VerifyEventArgs e)
{
eventLog1.WriteEntry("Verify Event Raised");
}
}
}
What is my mistake? please help me!
The Windows Service that I wrote, can raise custom events but cannot raise my dll events!

I know this thread is old, but I had this problem yesterday, and now I have finally found a solution, after many hours wasted.
The problem is that, the COM object must be created from an STA Thread, and then, for the events to be dispatched correctly, the same STA thread (exactly the same) must be pumping COM messages. This can be done calling Application.DoEvents() in a loop or Application.Run().
So here is my working code (it works, even as a non-interactive Windows Service in Vista+, I am using Windows 8.1)
Thread createComAndMessagePumpThread = new Thread(() =>
{
this.Device = new CZKEMClass(); //Here create COM object
Application.Run();
});
createComAndMessagePumpThread.SetApartmentState(ApartmentState.STA);
createComAndMessagePumpThread.Start();
After the device gets created you can register the events from any thread, and they get dispatched by the STA thread, that created the COM object.
In Windows Forms application, this worked without doing this, because the STA main thread run the form calling Application.Run(Form). Application.Run() then dispatch events like COM events and Windows GUI events, so there is no need to to the trick above.

Reviving this question as I've just been dealing with a related one. Apparently, the OP is using some COM STA objects which need an STA thread and a functional message pump loop to operate properly. The Windows Service execution model doesn't have that by default. Visit the linked answer for more details.

You cannot use events in Windows Service. Exists several causes why not but I would like to offer a solution just for zkemkeeper:
ZK released a zkemkeeper.dll as COM object for working with Windows Application. All device events will fired and not raised in your application when you run it as windows service. Try to add a reference System.Windows.Forms to the project and after successfully connect add row:
Application.Run();

Console.Writeline from EventHandler

I've written a simple async TCP-Server - it works well. But now I want to make an output of the received Data on the Console-Testprogram. And the problem is, this isn't working! If I connect the MainThread to the EventHandler the program does nothing. Debug is showing that the sc05Server_DataAvailable was called but then nothing happened. The program is still responsive.
Here The Code:
private void ReadCallback(IAsyncResult asyncResult)
{
Sc05BdClient sc05BdClient = asyncResult.AsyncState as Sc05BdClient;
if (sc05BdClient == null) return;
NetworkStream networkStream = sc05BdClient.NetworkStream;
int read = networkStream.EndRead(asyncResult);
if (read == 0)
{
lock (clients)
{
clients.Remove(sc05BdClient);
return;
}
}
string data = Encoding.GetString(sc05BdClient.Buffer, 0, read);
System.Diagnostics.Debug.Print(data);
OnDataAvailable(this, new DataAvailableEventArgs(data)); <---- here Handler is called
networkStream.BeginRead(sc05BdClient.Buffer, 0, sc05BdClient.Buffer.Length, ReadCallback, sc05BdClient);
}
public event EventHandler<DataAvailableEventArgs> DataAvailable;
protected virtual void OnDataAvailable(object sender, DataAvailableEventArgs e)
{
EventHandler<DataAvailableEventArgs> handler = DataAvailable;
if (handler != null)
handler(sender, e);
}
public class DataAvailableEventArgs : EventArgs
{
public string Data;
public DataAvailableEventArgs(string data)
{
Data = data;
}
}
The Main program:
class Program
{
static void Main()
{
Sc05BdServer sc05BdServer = new Sc05BdServer(IPAddress.Any, 2006);
sc05BdServer.DataAvailable += sc05BdServer_DataAvailable;
sc05BdServer.Start();
Console.ReadKey();
sc05BdServer.Stop();
}
static void sc05BdServer_DataAvailable(object sender, DataAvailableEventArgs e)
{
Console.WriteLine(e.Data); <--- this is called once
}
}
I think it has something to do with Threading - but I have no idea how to work with them.

You are probably experiencing some kind of race issue although Console should be immune to that. Check this question but note that I couldn't reproduce the problem: Strange behaviour of Console.ReadKey() with multithreading

Logging information to a windowed textbox

I am working on converting a console application into a windowed format and as someone who knows little about it but has had experience with a similar application already in window format in the past I figured it wouldn't be too hard.
So I created a form and added a textbox to it just to get the logging information to start with.
This console app used to run in a single thread, I have since added a second thread to allow the form to run side by side with the console for testing. (it runs fine in a single thread strangely now too).
This is the code I am using to write text to the form except that I am not getting ANYTHING at all on the form.
static Form1 f = new Form1();
delegate void SetTextCallback(string s);
private void SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (f.textBox1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(SetText);
f.textBox1.Invoke(d, new object[] { text });
}
else
{
f.textBox1.AppendText(text);
}
}
I can confirm that there is text entering the "text" variable but it is not getting to the form.
Any help would be appreciated.
This is the full file:
using System;
using System.Windows.Forms;
using Chraft.Properties;
using System.IO;
using Chraft.Plugins.Events.Args;
using Chraft.Plugins.Events;
namespace Chraft
{
public class Logger
{
private StreamWriter WriteLog;
private Server Server;
internal Logger(Server server, string file)
{
Server = server;
try
{
WriteLog = new StreamWriter(file, true);
WriteLog.AutoFlush = true;
}
catch
{
WriteLog = null;
}
}
~Logger()
{
try
{
WriteLog.Close();
}
catch
{
}
}
public void Log(LogLevel level, string format, params object[] arguments)
{
Log(level, string.Format(format, arguments));
}
public void Log(LogLevel level, string message)
{
//Event
LoggerEventArgs e = new LoggerEventArgs(this, level, message);
Server.PluginManager.CallEvent(Event.LOGGER_LOG, e);
if (e.EventCanceled) return;
level = e.LogLevel;
message = e.LogMessage;
//End Event
LogToConsole(level, message);
LogToForm(level, message);
LogToFile(level, message);
}
private void LogToConsole(LogLevel level, string message)
{
if ((int)level >= Settings.Default.LogConsoleLevel)
{
Console.WriteLine(Settings.Default.LogConsoleFormat, DateTime.Now, level.ToString().ToUpper(), message);
}
}
static Form1 f = new Form1();
delegate void SetTextCallback(string s);
private void SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (f.textBox1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(SetText);
f.textBox1.Invoke(d, new object[] { text });
}
else
{
f.textBox1.AppendText(text);
}
}
private void LogToForm(LogLevel level, string message)
{
if ((int)level >= Settings.Default.LogConsoleLevel)
{
SetText(DateTime.Now + level.ToString().ToUpper() + message);
}
}
private void LogToFile(LogLevel level, string message)
{
if ((int)level >= Settings.Default.LogFileLevel && WriteLog != null)
WriteLog.WriteLine(Settings.Default.LogFileFormat, DateTime.Now, level.ToString().ToUpper(), message);
}
public void Log(Exception ex)
{
//Event
LoggerEventArgs e = new LoggerEventArgs(this, LogLevel.Debug, ex.ToString(), ex);
Server.PluginManager.CallEvent(Event.LOGGER_LOG, e);
if (e.EventCanceled) return;
//End Event
Log(LogLevel.Debug, ex.ToString());
}
public enum LogLevel : int
{
Trivial = -1,
Debug = 0,
Info = 1,
Warning = 2,
Caution = 3,
Notice = 4,
Error = 5,
Fatal = 6
}
}
}

The problem is that you are creating two Form objects. One that is created in your Program.cs file:
Application.Run(new Form1());
And the one you created in your logger class
Form f = new Form1();
The one passed to Application.Run is the one that the user is interacting with. It has become visible and responds to user interaction because of the Application.Run call.
The one you created on your logger class just sits there in memory. Its TextBox is happily adding the text you ask it to, but that one isn't visible anywhere.
There are many ways to handle this situation. You could gain access to the correct Form object through Application.OpenForms, but a more appropriate way to handle it would be to add an event on the logger that the form can subscribe to and it can handle updating the TextBox in response to the event.
Updated
class LoggerLogEventArgs : EventArgs
{
public LoggerLogEventArgs(string message)
{
this.message = message;
}
private string message;
public string Message { get { return message; } }
}
class Logger
{
public event EventHandler<LoggerLogEventArgs> Logged;
protected virtual void OnLogged(LoggerLogEventArgs e)
{
EventHandler<LoggerLogEventArgs> handler = Logged;
if (handler != null)
handler(this, e);
}
// I would change this method name to LogToEvent
private void LogToForm(LogLevel level, string message)
{
if ((int)level >= Settings.Default.LogConsoleLevel)
{
OnLogged(new LoggerLogEventArgs(message));
}
}
}
class Form1 : Form
{
// Subscribe to the logger only when we are ready to display text
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
GetLog().Logged += new EventHandler<LoggerLogEventArgs>(logger_Logged);
}
// Unsubscribe from the logger before we are no longer ready to display text
protected override void OnHandleDestroyed(EventArgs e)
{
GetLog().Logged -= new EventHandler<LoggerLogEventArgs>(logger_Logged);
base.OnHandleDestroyed(e);
}
private void logger_Logged(object sender, LoggerLogEventArgs e)
{
if (InvokeRequired)
BeginInvoke(new EventHandler<LoggerLogEventArgs>(logger_Logged), e);
else
textBox1.AppendText(e.Message);
}
}

hello i try this it works ( I make a console application and I add a windows form)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Permissions;
using System.Windows.Forms;
namespace ConsoleApplication6
{
class Program
{
delegate void SetTextCallback(string s);
static Form1 f;
static void Main(string[] args)
{
f = new Form1();
f.Show();
SetText("test");
Console.ReadLine();
}
private static void SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (f.textBox1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(SetText);
f.textBox1.Invoke(d, new object[] { text });
}
else
{
f.textBox1.AppendText(text);
}
}
}
}

Simple Delegate Not Working

class SimpleDelegate
{
public delegate void LogHandler(string message);
public void Process(LogHandler logHandler)
{
if (logHandler != null)
{
Console.WriteLine("Process begin");
}
if (logHandler != null)
{
Console.WriteLine("Process end");
}
}
}
class FileLogger
{
FileStream fileStream;
StreamWriter writer;
public FileLogger(string fileName)
{
fileStream = new FileStream(fileName, FileMode.Create);
writer = new StreamWriter(fileStream);
}
public void Logger(string s)
{
writer.WriteLine(s);
}
public void Close()
{
writer.Close();
fileStream.Close();
}
}
class Program
{
static void Main(string[] args)
{
SimpleDelegate cp = new SimpleDelegate();
FileLogger fl = new FileLogger(#"C:\TEMP\MyLog.log");
SimpleDelegate.LogHandler handler = null;
handler += new SimpleDelegate.LogHandler(Logger);
handler += new SimpleDelegate.LogHandler(fl.Logger);
cp.Process(handler);
fl.Close();
}
static void Logger(string s)
{
Console.WriteLine("writing s " + s);
}
}
On executing I get following output:
Process begin
Process end
Press any key to continue . . .
Actually it should be:
Process begin
Process end
Process begin
Process end
Press any key to continue . . .
I am not able to figure out the mistake :(

You're only calling SimpleDelegate.Process once - why would you expect to see output twice?
You're never actually invoking the delegate... just testing it for nullity. You're testing that twice, once before writing "Process begin" and once before writing "Process end", but that's all.

I'm not sure if I'm getting the point ...
But you never call the logHandler in this code:
public void Process(LogHandler logHandler)
{
if (logHandler != null)
{
Console.WriteLine("Process begin");
}
if (logHandler != null)
{
Console.WriteLine("Process end");
}
}

I believe your confusion is around the fact that you called "LogHandler += ..." twice, but are only getting two outputs. Notice that the Process function you are calling doesn't do a loop that uses the LogHandler! That's why you're not getting the results you expect.
Also, the model you are using is just slightly off. Instead of directly using the delegate, it is better to create an event and subscribe to that.
public delegate void LogHandler(string message);
public event LogHandler OnLog;
...
OnLog += ...

I think this is what is happening
SimpleDelegate cp = new SimpleDelegate();
FileLogger fl = new FileLogger(#"C:\TEMP\MyLog.log");
cp.Process(null);
fl.Close();
That is handler is null, so that code never gets executed. You see your message once because of the call to cp.Process(null)