检测控制台应用程序何时关闭/关闭?

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我想让我的控制台应用程序安全地退出,这个应用程序将在Linux上使用Mono运行,但是我找不到一个解决方案来检测是否向它发送了信号,或者用户按下了ctrl+c。

在Windows上,有一个内核函数SetConsoleCtrlHandler,它可以完成这项工作,但是它不能在Mono上工作。

如何使控制台应用程序上的关闭事件安全退出?

提问于
用户回答回答于

你需要用Mono.UnixSignal,乔纳森·普赖尔发布了一个很好的样本:

在Mono页面上还有一个简短的例子:

// Catch SIGINT and SIGUSR1
UnixSignal[] signals = new UnixSignal [] {
    new UnixSignal (Mono.Unix.Native.Signum.SIGINT),
    new UnixSignal (Mono.Unix.Native.Signum.SIGUSR1),
};

Thread signal_thread = new Thread (delegate () {
    while (true) {
        // Wait for a signal to be delivered
        int index = UnixSignal.WaitAny (signals, -1);

        Mono.Unix.Native.Signum signal = signals [index].Signum;

        // Notify the main thread that a signal was received,
        // you can use things like:
        //    Application.Invoke () for Gtk#
        //    Control.Invoke on Windows.Forms
        //    Write to a pipe created with UnixPipes for server apps.
        //    Use an AutoResetEvent

        // For example, this works with Gtk#    
        Application.Invoke (delegate () { ReceivedSignal (signal); });
    }});
用户回答回答于

作为提供Unix和Windows实现的示例,请参阅下面。注意,在使用VisualStudio时,仍然可以包含Mono.Po6DLL。

我还添加了SIGTERM信号,因为这是由unix中的systemd在停止/重新启动应用程序作为服务时触发的。

接口公开退出事件。

public interface IExitSignal
{
    event EventHandler Exit;
}

Unix实现

public class UnixExitSignal : IExitSignal
{
    public event EventHandler Exit;

    UnixSignal[] signals = new UnixSignal[]{
        new UnixSignal(Mono.Unix.Native.Signum.SIGTERM), 
        new UnixSignal(Mono.Unix.Native.Signum.SIGINT),
        new UnixSignal(Mono.Unix.Native.Signum.SIGUSR1)
    };

    public UnixExitSignal()
    {
        Task.Factory.StartNew(() => 
        {
            // blocking call to wait for any kill signal
            int index = UnixSignal.WaitAny(signals, -1);

            if (Exit != null)
            {
                Exit(null, EventArgs.Empty);
            }

        });
    }

}

Windows实现

public class WinExitSignal : IExitSignal
{
    public event EventHandler Exit;

    [DllImport("Kernel32")]
    public static extern bool SetConsoleCtrlHandler(HandlerRoutine Handler, bool Add);

    // A delegate type to be used as the handler routine
    // for SetConsoleCtrlHandler.
    public delegate bool HandlerRoutine(CtrlTypes CtrlType);

    // An enumerated type for the control messages
    // sent to the handler routine.
    public enum CtrlTypes
    {
        CTRL_C_EVENT = 0,
        CTRL_BREAK_EVENT,
        CTRL_CLOSE_EVENT,
        CTRL_LOGOFF_EVENT = 5,
        CTRL_SHUTDOWN_EVENT
    }

    /// <summary>
    /// Need this as a member variable to avoid it being garbage collected.
    /// </summary>
    private HandlerRoutine m_hr;

    public WinExitSignal()
    {
        m_hr = new HandlerRoutine(ConsoleCtrlCheck);

        SetConsoleCtrlHandler(m_hr, true);

    }

    /// <summary>
    /// Handle the ctrl types
    /// </summary>
    /// <param name="ctrlType"></param>
    /// <returns></returns>
    private bool ConsoleCtrlCheck(CtrlTypes ctrlType)
    {
        switch (ctrlType)
        {
            case CtrlTypes.CTRL_C_EVENT:
            case CtrlTypes.CTRL_BREAK_EVENT:
            case CtrlTypes.CTRL_CLOSE_EVENT:
            case CtrlTypes.CTRL_LOGOFF_EVENT:
            case CtrlTypes.CTRL_SHUTDOWN_EVENT:
                if (Exit != null)
                {
                    Exit(this, EventArgs.Empty);
                }
                break;
            default:
                break;
        }

        return true;
    }


}

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