Capture console exit C#

ZeroKelvin_58444 0
Viewed 98831

I have a console application that contains quite a lot of threads. There are threads that monitor certain conditions and terminate the program if they are true. This termination can happen at any time.

I need an event that can be triggered when the program is closing so that I can cleanup all of the other threads and close all file handles and connections properly. I'm not sure if there is one already built into the .NET framework, so I'm asking before I write my own.

I was wondering if there was an event along the lines of:

MyConsoleProgram.OnExit += CleanupBeforeExit;
events console exit .net c#
10 Answers

I am not sure where I found the code on the web, but I found it now in one of my old projects. This will allow you to do cleanup code in your console, e.g. when it is abruptly closed or due to a shutdown...

[DllImport("Kernel32")]
private static extern bool SetConsoleCtrlHandler(EventHandler handler, bool add);

private delegate bool EventHandler(CtrlType sig);
static EventHandler _handler;

enum CtrlType
{
  CTRL_C_EVENT = 0,
  CTRL_BREAK_EVENT = 1,
  CTRL_CLOSE_EVENT = 2,
  CTRL_LOGOFF_EVENT = 5,
  CTRL_SHUTDOWN_EVENT = 6
}

private static bool Handler(CtrlType sig)
{
  switch (sig)
  {
      case CtrlType.CTRL_C_EVENT:
      case CtrlType.CTRL_LOGOFF_EVENT:
      case CtrlType.CTRL_SHUTDOWN_EVENT:
      case CtrlType.CTRL_CLOSE_EVENT:
      default:
          return false;
  }
}


static void Main(string[] args)
{
  // Some biolerplate to react to close window event
  _handler += new EventHandler(Handler);
  SetConsoleCtrlHandler(_handler, true);
  ...
}

Update

For those not checking the comments it seems that this particular solution does not work well (or at all) on Windows 7. The following thread talks about this

user_514280

Check also:

AppDomain.CurrentDomain.ProcessExit
user_1071020

It sounds like you have the threads directly terminating the application? Perhaps it would be better to have a thread signal the main thread to say that the application should be terminated.

On receiving this signal, the main thread can cleanly shutdown the other threads and finally close itself down.

Rob_10060

There is for WinForms apps;

Application.ApplicationExit += CleanupBeforeExit;

For Console apps, try

AppDomain.CurrentDomain.DomainUnload += CleanupBeforeExit;

But I am not sure at what point that gets called or if it will work from within the current domain. I suspect not.

user_308270

For those interested in VB.net. (I searched the internet and couldn't find an equivalent for it) Here it is translated into vb.net.

    <DllImport("kernel32")> _
    Private Function SetConsoleCtrlHandler(ByVal HandlerRoutine As HandlerDelegate, ByVal Add As Boolean) As Boolean
    End Function
    Private _handler As HandlerDelegate
    Private Delegate Function HandlerDelegate(ByVal dwControlType As ControlEventType) As Boolean
    Private Function ControlHandler(ByVal controlEvent As ControlEventType) As Boolean
        Select Case controlEvent
            Case ControlEventType.CtrlCEvent, ControlEventType.CtrlCloseEvent
                Console.WriteLine("Closing...")
                Return True
            Case ControlEventType.CtrlLogoffEvent, ControlEventType.CtrlBreakEvent, ControlEventType.CtrlShutdownEvent
                Console.WriteLine("Shutdown Detected")
                Return False
        End Select
    End Function
    Sub Main()
        Try
            _handler = New HandlerDelegate(AddressOf ControlHandler)
            SetConsoleCtrlHandler(_handler, True)
     .....
End Sub
user_5285370
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