notepad.cs

using System;
using System.Runtime.InteropServices;

namespace PInvoke
{
    internal class Program
    {
        [StructLayout(LayoutKind.Sequential)]
        public struct STARTUPINFO
        {
            public int cb;
            public IntPtr lpReserved;
            public IntPtr lpDesktop;
            public IntPtr lpTitle;
            public int dwX;
            public int dwY;
            public int dwXSize;
            public int dwYSize;
            public int dwXCountChars;
            public int dwYCountChars;
            public int dwFillAttribute;
            public int dwFlags;
            public short wShowWindow;
            public short cbReserved2;
            public IntPtr lpReserved2;
            public IntPtr hStdInput;
            public IntPtr hStdOutput;
            public IntPtr hStdError;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct PROCESS_INFORMATION
        {
            public IntPtr hProcess;
            public IntPtr hThread;
            public int dwProcessId;
            public int dwThreadId;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct SECURITY_ATTRIBUTES
        {
            public int nLength;
            public IntPtr lpSecurityDescriptor;
            public bool bInheritHandle;
        }

        [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        static extern bool CreateProcessW(string lpApplicationName, string lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
            ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandles, uint dwCreationFlags, IntPtr lpEnvironment,
            string lpCurrentDirectory, ref STARTUPINFO lpStartupInfo, out PROCESS_INFORMATION lpProcessInformation);

        static void Main(string[] args)
        {
            var si = new STARTUPINFO();
            si.cb = Marshal.SizeOf(si);

            var pa = new SECURITY_ATTRIBUTES();
            pa.nLength = Marshal.SizeOf(pa);

            var ta = new SECURITY_ATTRIBUTES();
            ta.nLength = Marshal.SizeOf(ta);

            var pi = new PROCESS_INFORMATION();

            var success = CreateProcessW(
                "C:\\Windows\\System32\\notepad.exe",
                null,
                ref pa,
                ref ta,
                false,
                0,
                IntPtr.Zero,
                "C:\\Windows\\System32",
                ref si,
                out pi);

            if (success)
                Console.WriteLine("Process created with PID: {0}.", pi.dwProcessId);
            else
                Console.WriteLine("Failed to create process. Error code: {0}.", Marshal.GetLastWin32Error());
        }
    }
}