C#: GC

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace FreeResource
{
    class TestConn
    {
        public void openConn(int i)
        {
            string connstr = "server=(local);uid=sa;pwd=aaa;database=Test;";
            SqlConnection conn = new SqlConnection(connstr);
            conn.Open();
            //conn.Close();
            //conn.Dispose();
            Console.WriteLine(i);
        }
    
    }

    class TestConn2 : IDisposable
    {
        SqlConnection conn;
        public TestConn2()
        {
            string connstr = "server=(local);uid=sa;pwd=aaa;database=Test;";
            this.conn = new SqlConnection(connstr);
        }

        public void openConn(int i)
        {

            this.conn.Open();            
            //conn.Close();
            //conn.Dispose();
            Console.WriteLine(i);
        }

        public void Dispose()
        {
            conn.Close();
            conn.Dispose();
        }
    }


    class Program
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < 10000; i++)
            {
                TestConn2 t = new TestConn2();
                t.openConn(i);
                t.Dispose();//必须手工调用，并非离开生存期之后就立即由.NET框架调用
            }
            
        }
    }
}