父进程在C#中终止时如何终止子进程

using System.Diagnostics;

ProcessStartInfo startInfo = new ProcessStartInfo("notepad.exe");
Process childProcess = new Process();
childProcess.StartInfo = startInfo;
childProcess.EnableRaisingEvents = true;
childProcess.Exited += new EventHandler(ChildProcess_Exited);
childProcess.Start();

private static void ChildProcess_Exited(object sender, EventArgs e)
{
    Process childProcess = (Process)sender;
    childProcess.Kill();
}

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

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
public static extern IntPtr CreateJobObject(IntPtr lpJobAttributes, string lpName);

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
public static extern bool SetInformationJobObject(IntPtr hJob, int JobObjectInfoClass, IntPtr lpJobObjectInfo, int cbJobObjectInfoLength);

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
public static extern bool AssignProcessToJobObject(IntPtr hJob, IntPtr hProcess);

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
public static extern bool CloseHandle(IntPtr hObject);

const int JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE = 2;

ProcessStartInfo startInfo = new ProcessStartInfo("notepad.exe");
Process childProcess = new Process();
childProcess.StartInfo = startInfo;
childProcess.Start();

IntPtr jobHandle = CreateJobObject(IntPtr.Zero, null);
IntPtr jobInfoPtr = Marshal.AllocHGlobal(sizeof(int));
Marshal.WriteInt32(jobInfoPtr, JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE);

SetInformationJobObject(jobHandle, 2, jobInfoPtr, sizeof(int));
AssignProcessToJobObject(jobHandle, childProcess.Handle);

Marshal.FreeHGlobal(jobInfoPtr);
CloseHandle(jobHandle);