有没有办法确保当我的进程终止时，我的程序生成的后台进程被杀死？

Question

基本上，子进程无限期地运行，直到在后台被杀死，当我的程序因任何原因终止时，我想清理它，即通过任务管理器。

目前，如果父进程没有运行，我有一段时间 (Process.GetProcessesByName("ParentProcess").Count() > 0) 循环并退出，但它看起来很脆弱，如果我希望它在调试器下工作Visual Studio 我必须添加“ParentProcess.vshost”或其他内容。

有没有什么方法可以确保子进程结束而不要求子进程知道父进程？ 我更喜欢托管代码中的解决方案，但如果没有，我可以 PInvoke。

编辑：传递 PID 似乎是一个更强大的解决方案，但出于好奇，如果子进程不是我的代码而是一些我无法控制的 exe 怎么办？ 有没有办法防止可能创建孤立的子进程？

Answer 1

如果子进程是您自己的代码，则可以在启动它时将父进程的 PID 传递给它。 然后，子进程可以使用 获取进程Process.GetProcessById 并订阅其 Exited 事件，带有一个处理程序，可以正常关闭（子）进程的其余部分。 请注意，您需要设置 EnableRaisingEvents<进程上的 /code>属性设置为 true。

Answer 2

如果子进程不是您自己的代码，您可以使用以下代码查找并终止所有子进程：

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace Util {
    public static class ProcessExtensions {
        public static void KillDescendants(this Process processToNotKillYet) {
            foreach (var eachProcess in Process.GetProcesses()) {
                if (eachProcess.ParentPid() == processToNotKillYet.Id) {
                    eachProcess.KillTree();
                }
            }
        }

        public static void KillTree(this Process processToKill) {
            processToKill.KillDescendants();
            processToKill.Kill();
        }

        public static PROCESS_BASIC_INFORMATION Info(this Process process) {
            var processInfo = new PROCESS_BASIC_INFORMATION();
            try {
                uint bytesWritten;
                NtQueryInformationProcess(process.Handle,
                                          0,
                                          ref processInfo,
                                          (uint)Marshal.SizeOf(processInfo),
                                          out bytesWritten); // == 0 is OK
            }
            catch (Win32Exception e) {
                if (!e.Message.Equals("Access is denied")) throw;
            }

            return processInfo;
        }

        public static int ParentPid(this Process process) {
            return process.Info().ParentPid;
        }

        [DllImport("ntdll.dll")]
        private static extern int NtQueryInformationProcess(
            IntPtr hProcess,
            int processInformationClass /* 0 */,
            ref PROCESS_BASIC_INFORMATION processBasicInformation,
            uint processInformationLength,
            out uint returnLength);

        [StructLayout(LayoutKind.Sequential)]
        public struct PROCESS_BASIC_INFORMATION {
            public int ExitStatus;
            public int PebBaseAddress;
            public int AffinityMask;
            public int BasePriority;
            public int Pid;
            public int ParentPid;
        }
    }
}

Answer 3

此类子进程的通用术语为孤儿进程。 请参阅链接的文章了解一些可能的解决方案。

Answer 4

这是我构建的一个小型实用程序应用程序的源代码
（它基于 Alan Hensel 解决方案，我发现它非常有用）。

它被称为ChildrenProcessKiller，它是一个观察程序，可以在父进程退出时杀死给定父进程的所有后代进程（即使父进程崩溃）

用法：

ChildrenProcessKiller.exe parentProcessId

警告：此代码“按原样”提供，并且可能杀死小婴儿;-)

ChildrenProcessKiller.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace ChildrenProcessKiller
{
  static class ChildrenProcessKiller
  {
    [STAThread]
    static void Main(string[] args)
    {
      Application.EnableVisualStyles();
      Application.SetCompatibleTextRenderingDefault(false);

      string message = "This is a watcher that enables to kill all descendants process of a given parent process\n";
      message += "when the parent process exits (even if the parent process crashes) \n\n";
      message += "Usage : " + Application.ExecutablePath + " parentProcessId";

      if (args.Length != 1)
      {
        MessageBox.Show(message);
        System.Environment.Exit(1);
      }

      int parentProcessId;
      if (!Int32.TryParse(args[0], out parentProcessId))
      {
        MessageBox.Show(message);
        System.Environment.Exit(1);
      }

      try
      {
        mParentProcess = Process.GetProcessById(parentProcessId);
      }
      catch (System.ArgumentException ex)
      {
        //Parent process cannot be found!
        System.Environment.Exit(2);
      }
      Run();
    }

    private static List<Process> mChildrenProcesses;
    private static Process mParentProcess;

    private static void Run()
    {
      int thisProcessId = Process.GetCurrentProcess().Id;
      while ( ! mParentProcess.HasExited )
      {
        RefreshChildrenProcesses();
        System.Threading.Thread.Sleep(1000);
      }

      foreach (Process childProcess in mChildrenProcesses)
      {
        if ((!childProcess.HasExited) && (childProcess.Id != thisProcessId))
        {
          KillGracefullyThenViolently(childProcess);
        }
      }
    }

    private static void KillGracefullyThenViolently(Process process)
    {
      if (process.HasExited)
        return;

      try
      {
        process.CloseMainWindow();
      }
      catch (PlatformNotSupportedException)
      {}
      catch (InvalidOperationException)
      {}//do nothing : this app is meant to be "unstoppable", unless the parent process has exited

      for (int i = 0; i < 15; i++)
      {
        System.Threading.Thread.Sleep(100);
        if (process.HasExited)
          return;
      }

      try
      {
        process.Kill();
      }
      catch (System.ComponentModel.Win32Exception)
      {}
      catch(NotSupportedException)
      {}
      catch(InvalidOperationException)
      {} //same comment here
    }

    private static void RefreshChildrenProcesses()
    {
      if (mParentProcess.HasExited)
        return;
      List<Process> newChildren;
      try
      {
        newChildren = Utils.ProcessTree.GetProcessDescendants(mParentProcess);
        mChildrenProcesses = newChildren;
      }
      catch (System.Exception ex)
      {
        ; 
      }
    }


  }
}

ProcessTree.cs

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.IO;
using System.Windows.Forms;

namespace Utils
{
  public static class ProcessTree
  {

    public static List<Process> GetProcessDescendants(Process process)
    {
      List<Process> result = new List<Process>();
      foreach (Process eachProcess in Process.GetProcesses())
      {
        if (ParentPid(eachProcess) == process.Id)
        {
          result.Add(eachProcess);
        }
      }
      return result;
    }

    public static void KillDescendants(Process processToNotKillYet) 
    {
      foreach (Process eachProcess in Process.GetProcesses()) 
      {
        if (ParentPid(eachProcess) == processToNotKillYet.Id) 
        {
          if (eachProcess.Id != Process.GetCurrentProcess().Id)
            KillTree(eachProcess);
        }
      }
    }

    public static void KillTree(Process processToKill) 
    {
      KillDescendants(processToKill);
      processToKill.Kill();
    }

    public static PROCESS_BASIC_INFORMATION Info(Process process) 
    {
      PROCESS_BASIC_INFORMATION processInfo = new PROCESS_BASIC_INFORMATION();
      try
      {
        uint bytesWritten;
        NtQueryInformationProcess(process.Handle,
                        0,
                        ref processInfo,
                        (uint)Marshal.SizeOf(processInfo),
                        out bytesWritten); // == 0 is OK
      }
      catch (Win32Exception e) 
      {
        if (!e.Message.Equals("Access is denied")) throw;
      }

      return processInfo;
    }

    public static int ParentPid(Process process) 
    {
      return Info(process).ParentPid;
    }

    [DllImport("ntdll.dll")]
    private static extern int NtQueryInformationProcess(
      IntPtr hProcess,
      int processInformationClass /* 0 */,
      ref PROCESS_BASIC_INFORMATION processBasicInformation,
      uint processInformationLength,
      out uint returnLength);

    [StructLayout(LayoutKind.Sequential)]
    public struct PROCESS_BASIC_INFORMATION 
    {
      public int ExitStatus;
      public int PebBaseAddress;
      public int AffinityMask;
      public int BasePriority;
      public int Pid;
      public int ParentPid;
    }
  }
}

Answer 5

将父进程 ID 作为命令行参数传递给子进程。

在子进程中使用 get Process by id 并订阅它的 Exit 事件或创建一个线程并调用 Process.WaitForExit