C# difference between connection.close() and connection.Dispose()

conn.Close(); //If you use this, no need to initialize SqlConnection , you can open using conn.Open();

//conn.Dispose();//If you use this, it completely release the connection object and cannot be reopen just calling Open method. We will have re-initialize the Connection object


So always use conn.Close();

Sample code............


using System;using System.Data;using System.Data.SqlClient;/// <summary>
/// Demonstrates how to work with SqlConnection objects/// </summary>class SqlConnectionDemo
{    static void Main()
    {        // 1. Instantiate the connection        SqlConnection conn = new SqlConnection(
            "Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI");

        SqlDataReader rdr = null;
        try        {            // 2. Open the connection            conn.Open();
            // 3. Pass the connection to a command object            SqlCommand cmd = new SqlCommand("select * from Customers", conn);
            //
            // 4. Use the connection
            //

            // get query results            rdr = cmd.ExecuteReader();
            // print the CustomerID of each record            while (rdr.Read())
            {
                Console.WriteLine(rdr[0]);
            }
        }
        finally        {            // close the reader            if (rdr != null)
            {
                rdr.Close();
            }
            // 5. Close the connection            if (conn != null)
            {
                conn.Close(); //If you use this, no need to initialize SqlConnection , you can open using conn.Open();

//conn.Dispose();//If you use this, it completely release the connection object and cannot be reopen just calling Open method. We will have re-initialize the Connection object
            }
        }
    }
}