/// 
    /// LINQ,重点是感悟from子句中的查询变量的灵活    /// 
    class Program    {        static void Main(string[] args)        {            //1单个form子句            string[] values = { "LINQ学习","LINQ基本语句","from子句","单个from子句"};            var value = from v in values                        where v.IndexOf("LINQ") > -1                        select new { v, v.Length };            foreach (var n in value)            {                Console.WriteLine("{0},{1}",n.v,n.Length );            }            Console.ReadKey(false);            //2使用LINQ查询ArrayList            ArrayList gList = new ArrayList();            gList.Add(new GustInfo {  Name="DebugLZQ", Age=26, Tel="88888888"});            gList.Add(new GustInfo { Name="博客园",Age=6, Tel ="666666"});            gList.Add(new GustInfo { Name = "M&MSoft", Age =9, Tel = "55555" });            var query = from GustInfo gust in gList                        where gust.Age > 9                        select gust;//范围变量gust制定了数据类型            foreach (GustInfo g in query)            {                Console.WriteLine("{0} 年龄:{1} 电话:{2}",g.Name,g.Age,g.Tel );            }            Console.ReadKey(false);            //3复合from子句            List
    
      gList2 = new List
     
      ()             {                new GustInfo2{ Name="DebugLZQ",Age=26,TelTable=new List
      
       (){"8888888","138******"}},                new GustInfo2{ Name="博客园",Age=6,TelTable =new List
       
        (){"666666","138******"}},                new GustInfo2{ Name="M&MSoft",Age=9,TelTable=new List
        
         (){"55555","138******"}}            };            //gust、tel都是查询变量,作用域为当前查询语句！！！            var query2 = from gust in gList2                         from tel in gust.TelTable                          where tel.IndexOf("5555") > -1                         select gust;            foreach (var g in query2)            {                Console.WriteLine("{0} 年龄{1}",g.Name,g.Age );                foreach (var t in g.TelTable)                {                    Console.WriteLine("电话：{0}",t);                }            }            Console.ReadKey(false);            //4多个from子句            var query3 = from GustInfo gust in gList                         where gust.Age > 6                         from GustInfo2 gust2 in gList2                         where gust2.Age> 9                         select new { gust, gust2 };//查询结果定制            foreach (var g in query3)            {                Console.WriteLine("{0}  {1}", g.gust.Name, g.gust2.Name);            }            Console.ReadKey(false);        }    }