我有一个包含相当多线程的控制台应用程序。有些线程监视某些条件并在满足条件时终止程序。这种终止可能随时发生。
我需要一个可以在程序关闭时触发的事件，以便我可以清理所有其他线程并正确关闭所有文件句柄和连接。我不确定 .NET 框架中是否已经内置了一个框架，所以我在编写自己的框架之前先询问一下。
我想知道是否有类似的事件：
MyConsoleProgram.OnExit += CleanupBeforeExit;
我不确定在网上哪里找到了代码，但我现在在我的一个旧项目中找到了它。这将允许您在控制台中执行清理代码，例如当它突然关闭或由于关闭而...
[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);
...
}
更新
对于那些没有检查评论的人来说，这个特定的解决方案似乎在 Windows 7 上不工作得很好（或根本不工作）。下面的thread讲到了这个
完整的工作示例，与 ctrl-c 一起使用，用 X 关闭窗口并终止：
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 boilerplate 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..");
}
}
}
还检查：
AppDomain.CurrentDomain.ProcessExit
我遇到了类似的问题，只是我的控制台应用程序将在无限循环中运行，中间有一个抢占式语句。这是我的解决方案：
class Program
{
static int Main(string[] args)
{
// Init Code...
Console.CancelKeyPress += Console_CancelKeyPress; // Register the function to cancel event
// I do my stuffs
while ( true )
{
// Code ....
SomePreemptiveCall(); // The loop stucks here wating function to return
// Code ...
}
return 0; // Never comes here, but...
}
static void Console_CancelKeyPress(object sender, ConsoleCancelEventArgs e)
{
Console.WriteLine("Exiting");
// Termitate what I have to terminate
Environment.Exit(-1);
}
}
听起来你有线程直接终止应用程序？也许让一个线程向主线程发出信号以告知应用程序应该终止会更好。
收到此信号后，主线程可以干净地关闭其他线程，并最终关闭自己。
ZeroKelvin 的答案适用于 Windows 10 x64、.NET 4.6 控制台应用程序。对于那些不需要处理 CtrlType 枚举的人，这里有一个非常简单的方法来挂钩框架的关闭：
class Program
{
private delegate bool ConsoleCtrlHandlerDelegate(int sig);
[DllImport("Kernel32")]
private static extern bool SetConsoleCtrlHandler(ConsoleCtrlHandlerDelegate handler, bool add);
static ConsoleCtrlHandlerDelegate _consoleCtrlHandler;
static void Main(string[] args)
{
_consoleCtrlHandler += s =>
{
//DoCustomShutdownStuff();
return false;
};
SetConsoleCtrlHandler(_consoleCtrlHandler, true);
}
}
从处理程序返回 FALSE 告诉框架我们没有“处理”控制信号，并且使用该进程的处理程序列表中的下一个处理程序函数。如果没有一个处理程序返回 TRUE，则调用默认处理程序。
请注意，当用户执行注销或关闭时，Windows 不会调用回调，而是立即终止。
适用于 WinForms 应用程序；
Application.ApplicationExit += CleanupBeforeExit;
对于控制台应用程序，请尝试
AppDomain.CurrentDomain.DomainUnload += CleanupBeforeExit;
但我不确定在什么时候调用它或者它是否会在当前域内工作。我怀疑不是。
Visual Studio 2015 + Windows 10
代码：
using System;
using System.Linq;
using System.Runtime.InteropServices;
using System.Threading;
namespace YourNamespace
{
class Program
{
// if you want to allow only one instance otherwise remove the next line
static Mutex mutex = new Mutex(false, "YOURGUID-YOURGUID-YOURGUID-YO");
static ManualResetEvent run = new ManualResetEvent(true);
[DllImport("Kernel32")]
private static extern bool SetConsoleCtrlHandler(EventHandler handler, bool add);
private delegate bool EventHandler(CtrlType sig);
static EventHandler exitHandler;
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 ExitHandler(CtrlType sig)
{
Console.WriteLine("Shutting down: " + sig.ToString());
run.Reset();
Thread.Sleep(2000);
return false; // If the function handles the control signal, it should return TRUE. If it returns FALSE, the next handler function in the list of handlers for this process is used (from MSDN).
}
static void Main(string[] args)
{
// if you want to allow only one instance otherwise remove the next 4 lines
if (!mutex.WaitOne(TimeSpan.FromSeconds(2), false))
{
return; // singleton application already started
}
exitHandler += new EventHandler(ExitHandler);
SetConsoleCtrlHandler(exitHandler, true);
try
{
Console.BackgroundColor = ConsoleColor.Gray;
Console.ForegroundColor = ConsoleColor.Black;
Console.Clear();
Console.SetBufferSize(Console.BufferWidth, 1024);
Console.Title = "Your Console Title - XYZ";
// start your threads here
Thread thread1 = new Thread(new ThreadStart(ThreadFunc1));
thread1.Start();
Thread thread2 = new Thread(new ThreadStart(ThreadFunc2));
thread2.IsBackground = true; // a background thread
thread2.Start();
while (run.WaitOne(0))
{
Thread.Sleep(100);
}
// do thread syncs here signal them the end so they can clean up or use the manual reset event in them or abort them
thread1.Abort();
}
catch (Exception ex)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.Write("fail: ");
Console.ForegroundColor = ConsoleColor.Black;
Console.WriteLine(ex.Message);
if (ex.InnerException != null)
{
Console.WriteLine("Inner: " + ex.InnerException.Message);
}
}
finally
{
// do app cleanup here
// if you want to allow only one instance otherwise remove the next line
mutex.ReleaseMutex();
// remove this after testing
Console.Beep(5000, 100);
}
}
public static void ThreadFunc1()
{
Console.Write("> ");
while ((line = Console.ReadLine()) != null)
{
if (line == "command 1")
{
}
else if (line == "command 1")
{
}
else if (line == "?")
{
}
Console.Write("> ");
}
}
public static void ThreadFunc2()
{
while (run.WaitOne(0))
{
Thread.Sleep(100);
}
// do thread cleanup here
Console.Beep();
}
}
}
Charle B 在对 flq 的评论中提到的链接
内心深处说：
如果链接到 user32，SetConsoleCtrlHandler 将无法在 windows7 上工作线程中的其他一些地方建议创建一个隐藏窗口。所以我创建了一个 winform 并在 onload 中附加到控制台并执行原始 Main。 然后 SetConsoleCtrlHandle 工作正常（SetConsoleCtrlHandle 按照 flq 的建议调用）
public partial class App3DummyForm : Form
{
private readonly string[] _args;
public App3DummyForm(string[] args)
{
_args = args;
InitializeComponent();
}
private void App3DummyForm_Load(object sender, EventArgs e)
{
AllocConsole();
App3.Program.OriginalMain(_args);
}
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool AllocConsole();
}
<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
using System.Runtime.InteropServices;
partial class Program
{
[LibraryImport("kernel32.dll", SetLastError = true)]
static partial void SetConsoleCtrlHandler(Action callback, [MarshalAs(UnmanagedType.Bool)] bool add = true);
static void Main()
{
SetConsoleCtrlHandler(() => {
Console.WriteLine("Your cleanup code here");
});
Console.ReadLine();
}
}
请注意，如果您需要知道关闭应用程序的原因，则必须使用其他答案中提到的delegate
。