Displaying a file which is located in a folder

string path=@"c:\";
string[] files = System.IO.Directory.GetFiles(path);

// ...

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Files_Folder;
using System.IO;
using System.Data;
namespace WriteListFileFolder
{
    class Program
    {
        static void Main(string[] args)
        {
            DataTable DtTblList;
            DtTblList = new DataTable();
            DtTblList.Columns.Add("SrNo", typeof(int));
            DtTblList.Columns.Add("EntryType", typeof(int));
            DtTblList.Columns.Add("Path", typeof(string));

            GetFileFolders(ref DtTblList, "D:\\GSDIntegration");
            DtTblList.WriteXml("D\\XmlFile.xml");
        }
        static void GetFileFolders(ref DataTable DtTblList, string FolderPath)
        {
            string[] ListDirectory = Directory.GetDirectories( FolderPath);
            if (ListDirectory.Length > 0)
            {
                for (int n = 0; n < ListDirectory.Length; n++)
                {
                    DataRow _D = DtTblList.NewRow();
                    _D["SrNo"] = DtTblList.Rows.Count + 1; _D["EntryType"] = 1;
                    _D["Path"] = ListDirectory[n]; DtTblList.Rows.Add(_D);
                    GetFileFolders(ref DtTblList, ListDirectory[n]);
                }
            }
            else
            {
                string[] ListOfFiles = Directory.GetFiles(FolderPath);
                for (int i = 0; i < ListOfFiles.Length; i++)
                {
                    DataRow _D = DtTblList.NewRow();
                    _D["SrNo"] = DtTblList.Rows.Count + 1; _D["EntryType"] = 2;
                    _D["Path"] = ListOfFiles[i]; DtTblList.Rows.Add(_D);
                }
            }
        }
    }
}