Какие значения у параметров функции Win32 API??? (на примере CreateFile)

    struct SECURITY_ATTRIBUTES
    {
        internal long nLength;
        internal Int16 lpSecurityDescriptor;
        internal bool bInheritHandle;
    }
    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    public static extern IntPtr CreateFile(
       String lpFileName,
       Int32 dwDesiredAccess,
       Int32 dwShareMode,
       SECURITY_ATTRIBUTES lpSecurityAttributes,
       Int32 dwCreationDisposition,
       Int32 dwFlagsAndAttributes,
       IntPtr hTemplateFile);
 
...
 
      txt.Text += CreateFile("C:\\out.txt", long GENERIC_READ, long FILE_SHARE_READ, SECURITY_ATTRIBUTES atr, long OPEN_EXISTING, long FILE_ATTRIBUTE_NORMAL, ref GENERIC_READ);

    public const uint GENERIC_READ = 0x80000000;
    public const short FILE_SHARE_READ = 0x00000001;
    public const uint OPEN_EXISTING = 3;
    public const short FILE_ATTRIBUTE_NORMAL = 0x80;
    public const short INVALID_HANDLE_VALUE = -1;
 
    struct SECURITY_ATTRIBUTES
    {
        internal Int32 nLength;
        internal IntPtr lpSecurityDescriptor;
        internal bool bInheritHandle;
    }
    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    public static extern IntPtr CreateFile(//ошибка здесь
       String lpFileName,
       Int32 dwDesiredAccess,
       Int32 dwShareMode,
       SECURITY_ATTRIBUTES lpSecurityAttributes,
       Int32 dwCreationDisposition,
       Int32 dwFlagsAndAttributes,
       IntPtr hTemplateFile);
 
      SECURITY_ATTRIBUTES atr = new SECURITY_ATTRIBUTES();
        CreateFile("C:\\out.txt",GENERIC_READ,FILE_SHARE_READ,atr,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
        d.Text += (string)CreateFile;

using System.IO;
using System.Runtime.InteropServices;
 
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        [DllImport("Kernel32.dll")]
 
        static extern IntPtr CreateFile(
                        string filename,
                        [MarshalAs(UnmanagedType.U4)]FileAccess fileaccess,
                        [MarshalAs(UnmanagedType.U4)]FileShare fileshare,
                        int securityattributes,
                        [MarshalAs(UnmanagedType.U4)]FileMode creationdisposition,
                        int flags,
                        IntPtr template);
        private void button1_Click(object sender, EventArgs e)
        {
            IntPtr ptr = CreateFile("text.txt", FileAccess.ReadWrite,
                      FileShare.ReadWrite, 0, FileMode.Create, 0, IntPtr.Zero);
            MessageBox.Show("OK");
        }
    }
}