如何在C#中读取另一个进程的命令行参数？

using System;
using System.Runtime.InteropServices;

public class CommandLineReader
{
    [DllImport("kernel32.dll")]
    public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);

    [DllImport("kernel32.dll")]
    public static extern bool ReadProcessMemory(int hProcess, int lpBaseAddress, byte[] lpBuffer, int dwSize, ref int lpNumberOfBytesRead);

    public static string GetCommandLine(int processId)
    {
        IntPtr processHandle = OpenProcess(0x0410, false, processId);
        if (processHandle == IntPtr.Zero)
        {
            return null;
        }

        int pSize = Marshal.SizeOf(typeof(PEB)) + 1024;
        byte[] buffer = new byte[pSize];
        int bytesRead = 0;

        if (!ReadProcessMemory((int)processHandle, 0x00400000, buffer, pSize, ref bytesRead))
        {
            return null;
        }

        int offset = BitConverter.ToInt32(buffer, 0x00000230);
        int size = BitConverter.ToInt32(buffer, offset + 0x00000040);
        string commandLine = System.Text.Encoding.Unicode.GetString(buffer, offset + 0x00000044, size * 2);

        return commandLine;
    }
}

[StructLayout(LayoutKind.Sequential)]
public struct PEB
{
    public byte[] reserved1;
    public byte[] beingDebugged;
    public byte[] reserved2;
    public IntPtr ldr;
    public IntPtr processParameters;
    public byte[] reserved3;
    public IntPtr atlThunkSListPtr;
    public byte[] reserved4;
    public IntPtr reserved5;
    public IntPtr reserved6;
    public IntPtr reserved7;
    public byte[] reserved8;
}