static void Main(String[] args)        {            Console.WriteLine("--------");            string myconn = "Database='test';Data Source=localhost;User ID=root;Password=123456;CharSet=utf8;";            //需要执行的SQL语句            string mysql = "SELECT * from users";            //创建数据库连接            MySqlConnection myconnection = new MySqlConnection(myconn);            myconnection.Open();            //创建MySqlCommand对象            MySqlCommand mycommand = new MySqlCommand(mysql, myconnection);            //通过MySqlCommand的ExecuteReader()方法构造DataReader对象            MySqlDataReader myreader = mycommand.ExecuteReader();            //int size = 1024;            //int sizeCnt = (int)Math.Ceiling((double)dataGrid.RowCount / (double)2000);            StreamWriter write = new StreamWriter("F:\\test.csv", false, Encoding.Default, 1024 * 4);            write.Write("ID" + "," + "user_name" + "," +"user_passwd");            write.WriteLine();            while (myreader.Read())            {                string Tem = myreader.GetInt32(0) + "," + myreader.GetString(1) + "," + myreader.GetString(2);                write.WriteLine(Tem);            }            write.Flush();            write.Close();            myreader.Close();            myconnection.Close();        }