.NET控制台应用程序退出事件

Question

在.NET中,是否有一种方法(如事件)用于检测控制台应用程序何时退出？我需要清理一些线程和COM对象.

我正在从控制台应用程序运行一个没有表单的消息循环.我正在使用的DCOM组件似乎要求应用程序泵消息.

我已经尝试向Process.GetCurrentProcess.Exited和Process.GetCurrentProcess.Disposed添加一个处理程序.

我还尝试向Application.ApplicationExit和Application.ThreadExit事件添加处理程序,但它们没有触发.也许那是因为我没有使用表格.

Answer 1

您可以使用以下ProcessExit事件AppDomain:

class Program
{
    static void Main(string[] args)
    {
        AppDomain.CurrentDomain.ProcessExit += new EventHandler(CurrentDomain_ProcessExit);           
        // do some work

    }

    static void CurrentDomain_ProcessExit(object sender, EventArgs e)
    {
        Console.WriteLine("exit");
    }
}

更新

这是一个完整的示例程序,在单独的线程上运行一个空的"消息泵",允许用户在控制台中输入一个quit命令来正常关闭应用程序.在MessagePump中循环之后,您可能希望以一种很好的方式清理线程使用的资源.由于以下几个原因,最好在ProcessExit中执行此操作:

• 避免交叉线程问题; 如果在MessagePump线程上创建了外部COM对象,那么在那里处理它们会更容易.
• ProcessExit有一个时间限制(默认为3秒),因此如果清理很耗时,如果在该事件处理程序中进行了修改,则可能会失败.

这是代码:

class Program
{
    private static bool _quitRequested = false;
    private static object _syncLock = new object();
    private static AutoResetEvent _waitHandle = new AutoResetEvent(false);

    static void Main(string[] args)
    {
        AppDomain.CurrentDomain.ProcessExit += new EventHandler(CurrentDomain_ProcessExit);
        // start the message pumping thread
        Thread msgThread = new Thread(MessagePump);
        msgThread.Start();
        // read input to detect "quit" command
        string command = string.Empty;
        do
        {
            command = Console.ReadLine();
        } while (!command.Equals("quit", StringComparison.InvariantCultureIgnoreCase));
        // signal that we want to quit
        SetQuitRequested();
        // wait until the message pump says it's done
        _waitHandle.WaitOne();
        // perform any additional cleanup, logging or whatever
    }

    private static void SetQuitRequested()
    {
        lock (_syncLock)
        {
            _quitRequested = true;
        }
    }

    private static void MessagePump()
    {
        do
        {
            // act on messages
        } while (!_quitRequested);
        _waitHandle.Set();
    }

    static void CurrentDomain_ProcessExit(object sender, EventArgs e)
    {
        Console.WriteLine("exit");
    }
}

Answer 2

这是一个完整的,非常简单的.Net解决方案,适用于所有版本的Windows.只需将其粘贴到一个新项目中,运行它并尝试CTRL-C来查看它如何处理它:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;

namespace TestTrapCtrlC{
    public class Program{
        static bool exitSystem = false;

        #region Trap application termination
        [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) {
            Console.WriteLine("Exiting system due to external CTRL-C, or process kill, or shutdown");

            //do your cleanup here
            Thread.Sleep(5000); //simulate some cleanup delay

            Console.WriteLine("Cleanup complete");

            //allow main to run off
             exitSystem = true;

            //shutdown right away so there are no lingering threads
            Environment.Exit(-1);

            return true;
        }
        #endregion

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

            //start your multi threaded program here
            Program p = new Program();
            p.Start();

            //hold the console so it doesn’t run off the end
            while(!exitSystem) {
                Thread.Sleep(500);
            }
        }

        public void Start() {
            // start a thread and start doing some processing
            Console.WriteLine("Thread started, processing..");
        }
    }
 }

Answer 3

该应用程序是一个服务器,它只运行直到系统关闭或接收到Ctrl + C或控制台窗口关闭.

由于应用程序的特殊性,"优雅地"退出是不可行的.(可能是我可以编写另一个会发送"服务器关闭"消息的应用程序,但这对于一个应用程序来说是过度的,但对于某些情况(例如服务器(实际操作系统)实际关闭时)仍然不够.)

由于这些情况,我添加了一个" ConsoleCtrlHandler ",我停止我的线程并清理我的COM对象等...

Public Declare Auto Function SetConsoleCtrlHandler Lib "kernel32.dll" (ByVal Handler As HandlerRoutine, ByVal Add As Boolean) As Boolean

Public Delegate Function HandlerRoutine(ByVal CtrlType As CtrlTypes) As Boolean

Public Enum CtrlTypes
  CTRL_C_EVENT = 0
  CTRL_BREAK_EVENT
  CTRL_CLOSE_EVENT
  CTRL_LOGOFF_EVENT = 5
  CTRL_SHUTDOWN_EVENT
End Enum

Public Function ControlHandler(ByVal ctrlType As CtrlTypes) As Boolean
.
.clean up code here
.
End Function

Public Sub Main()
.
.
.
SetConsoleCtrlHandler(New HandlerRoutine(AddressOf ControlHandler), True)
.
.
End Sub

这种设置似乎完美无缺.这是一个链接到同一件事的一些C#代码.

Answer 4

对于CTRL + C案例,您可以使用:

// Tell the system console to handle CTRL+C by calling our method that
// gracefully shuts down.
Console.CancelKeyPress += new ConsoleCancelEventHandler(Console_CancelKeyPress);


static void Console_CancelKeyPress(object sender, ConsoleCancelEventArgs e)
{
            Console.WriteLine("Shutting down...");
            // Cleanup here
            System.Threading.Thread.Sleep(750);
}