我希望能够在 C# 控制台应用程序中捕获CTRL+ C，以便在退出之前进行一些清理。这样做的最佳方法是什么？
Nick R
问问题
141408 次
9 回答
263
Console.CancelKeyPress事件用于此目的。这是它的使用方式：
public static void Main(string[] args)
{
Console.CancelKeyPress += delegate {
// call methods to clean up
};
while (true) {}
}
当用户按下 Ctrl + C 时，委托中的代码运行并且程序退出。这允许您通过调用必要的方法来执行清理。请注意，委托执行后没有代码。
在其他情况下，这不会削减它。例如，如果程序当前正在执行无法立即停止的重要计算。在这种情况下，正确的策略可能是在计算完成后告诉程序退出。以下代码给出了如何实现的示例：
class MainClass
{
private static bool keepRunning = true;
public static void Main(string[] args)
{
Console.CancelKeyPress += delegate(object sender, ConsoleCancelEventArgs e) {
e.Cancel = true;
MainClass.keepRunning = false;
};
while (MainClass.keepRunning) {
// Do your work in here, in small chunks.
// If you literally just want to wait until ctrl-c,
// not doing anything, see the answer using set-reset events.
}
Console.WriteLine("exited gracefully");
}
}
此代码与第一个示例之间的区别在于e.Cancel设置为 true，这意味着在委托之后继续执行。如果运行，程序会等待用户按下 Ctrl + C。当发生这种情况时，keepRunning变量会更改值，从而导致 while 循环退出。这是一种让程序优雅退出的方法。
于 2009-05-30T13:15:39.833 回答
138
于 2008-10-07T10:24:16.460 回答
118
我想补充一下乔纳斯的回答。在 a 上旋转会导致 100% 的 CPU 使用率，并在等待+bool时浪费大量精力无所事事。CTRLC
更好的解决方案是使用 aManualResetEvent来实际“等待” CTRL+ C：
static void Main(string[] args) {
var exitEvent = new ManualResetEvent(false);
Console.CancelKeyPress += (sender, eventArgs) => {
eventArgs.Cancel = true;
exitEvent.Set();
};
var server = new MyServer(); // example
server.Run();
exitEvent.WaitOne();
server.Stop();
}
于 2012-12-16T07:28:40.717 回答
31
这是一个完整的工作示例。粘贴到空的 C# 控制台项目中：
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..");
}
}
}
于 2014-04-10T18:50:34.073 回答
7
这个问题非常类似于：
这是我解决这个问题的方法，并处理了用户按 X 和 Ctrl-C 的问题。注意 ManualResetEvents 的使用。这些将导致主线程休眠，从而释放 CPU 以在等待退出或清理时处理其他线程。注意：有必要在 main 结束时设置 TerminationCompletedEvent。不这样做会导致由于操作系统在终止应用程序时超时而导致不必要的终止延迟。
namespace CancelSample
{
using System;
using System.Threading;
using System.Runtime.InteropServices;
internal class Program
{
/// <summary>
/// Adds or removes an application-defined HandlerRoutine function from the list of handler functions for the calling process
/// </summary>
/// <param name="handler">A pointer to the application-defined HandlerRoutine function to be added or removed. This parameter can be NULL.</param>
/// <param name="add">If this parameter is TRUE, the handler is added; if it is FALSE, the handler is removed.</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("Kernel32")]
private static extern bool SetConsoleCtrlHandler(ConsoleCloseHandler handler, bool add);
/// <summary>
/// The console close handler delegate.
/// </summary>
/// <param name="closeReason">
/// The close reason.
/// </param>
/// <returns>
/// True if cleanup is complete, false to run other registered close handlers.
/// </returns>
private delegate bool ConsoleCloseHandler(int closeReason);
/// <summary>
/// Event set when the process is terminated.
/// </summary>
private static readonly ManualResetEvent TerminationRequestedEvent;
/// <summary>
/// Event set when the process terminates.
/// </summary>
private static readonly ManualResetEvent TerminationCompletedEvent;
/// <summary>
/// Static constructor
/// </summary>
static Program()
{
// Do this initialization here to avoid polluting Main() with it
// also this is a great place to initialize multiple static
// variables.
TerminationRequestedEvent = new ManualResetEvent(false);
TerminationCompletedEvent = new ManualResetEvent(false);
SetConsoleCtrlHandler(OnConsoleCloseEvent, true);
}
/// <summary>
/// The main console entry point.
/// </summary>
/// <param name="args">The commandline arguments.</param>
private static void Main(string[] args)
{
// Wait for the termination event
while (!TerminationRequestedEvent.WaitOne(0))
{
// Something to do while waiting
Console.WriteLine("Work");
}
// Sleep until termination
TerminationRequestedEvent.WaitOne();
// Print a message which represents the operation
Console.WriteLine("Cleanup");
// Set this to terminate immediately (if not set, the OS will
// eventually kill the process)
TerminationCompletedEvent.Set();
}
/// <summary>
/// Method called when the user presses Ctrl-C
/// </summary>
/// <param name="reason">The close reason</param>
private static bool OnConsoleCloseEvent(int reason)
{
// Signal termination
TerminationRequestedEvent.Set();
// Wait for cleanup
TerminationCompletedEvent.WaitOne();
// Don't run other handlers, just exit.
return true;
}
}
}
于 2015-01-22T04:23:02.507 回答
3
Console.TreatControlCAsInput = true;对我有用。
于 2014-08-04T11:52:02.753 回答
2
我可以在退出之前进行一些清理工作。这样做的最佳方法是什么这才是真正的目标：陷阱退出，制作自己的东西。上面的答案都没有正确。因为，Ctrl+C 只是退出应用程序的众多方法之一。
它需要 dotnet c# 中的什么 - 所谓的取消令牌传递给Host.RunAsync(ct)然后，在退出信号陷阱中，对于 Windows，它将是
private static readonly CancellationTokenSource cts = new CancellationTokenSource();
public static int Main(string[] args)
{
// For gracefull shutdown, trap unload event
AppDomain.CurrentDomain.ProcessExit += (sender, e) =>
{
cts.Cancel();
exitEvent.Wait();
};
Console.CancelKeyPress += (sender, e) =>
{
cts.Cancel();
exitEvent.Wait();
};
host.RunAsync(cts);
Console.WriteLine("Shutting down");
exitEvent.Set();
return 0;
}
...
于 2020-05-06T19:18:06.743 回答
2
检测 SIGTERM 和 ctrl+c：
CancellationTokenSource ctSource = new();
CancellationToken ct = ctSource.Token;
void ExitHandler()
{
// You can add any arbitrary global clean up
Console.WriteLine("Exiting...");
ctSource.Cancel();
}
// Assign exit handler to be called when the process is terminated
// or the user hits CTRL+C
AppDomain.CurrentDomain.ProcessExit += (sender, args) => ExitHandler();
Console.CancelKeyPress += (sender, args) => ExitHandler();
// Then you can use the cancellation token to check for exit:
Console.WriteLine("Ready to gracefully shut down!");
while (!ct.IsCancellationRequested)
{
Console.WriteLine($"Exit not detected, waiting another 10s.");
Task.Delay(10000, ct).Wait(ct);
}
于 2021-11-14T21:31:39.547 回答
-1
就我而言，我将异步 lambda 传递给Console.CancelKeyPress，但它不起作用。
于 2021-02-25T16:58:58.043 回答