How to Change the Master Page for All Sites in Sharepoint 2010 Using Console Application

 Change the Master Page for All Sites in Sharepoint 2010 Using Console Application:


using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Collections;
using System.Text;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Administration;

namespace UpdateMasterPages
{
    class Program
    {
          static void Main(string[] args)
        {
            using (SPSite currentSite = new SPSite("http://server/sites/"))
            {
                SPWebCollection webCollection = currentSite.AllWebs;
                foreach (SPWeb web in webCollection)
                {
                    string masterPageUrl = string.Format("{0}/_catalogs/masterpage/custom.master", 
                   currentSite.ServerRelativeUrl).Replace("//", "/");
                    web.CustomMasterUrl = masterPageUrl;
                    web.MasterUrl = masterPageUrl;
                    web.Update();
                    //web.AllowUnsafeUpdates = true;
                    Trace(web.Title + "********" + web.Url);
                }
            }
        }
            public static void Trace(string stritrace)
            {
            Stream codeFile = File.Open("c:\\Logs.txt", FileMode.Append);
            StreamWriter Tex = new StreamWriter(codeFile); ;
            Tex.WriteLine(DateTime.Now.ToString() + " " + stritrace);
            Tex.Write(Tex.NewLine);
            Tex.Close();
            }
    }
}