C# connection to mysql database and data processing, Chinese garbled problem

using MySql.Data.MySqlClient;//Add a reference and add a command space

class MyDb_mysql
    {
        MySqlConnection mycon = null;//mysql connection object
        public MyDb_mysql() { }
        public MyDb_mysql(string host,string user,string pwd,string database) {
            string constr = string.Format("server={0};User Id={1};password={2};database={3};charset=utf8;",host,user,pwd,database);// charset=utf8; Solve the problem of Chinese garbled characters
            mycon = new MySqlConnection(constr);
            mycon.Open();
        }
        /// <summary>
        /// Query data
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public DataTable Select(string sql)
        {
            try
            {
                MySqlCommand mycmd = new MySqlCommand(sql, mycon);
                MySqlDataAdapter da = new MySqlDataAdapter(mycmd);
                DataTable dt = new DataTable();
                da.Fill(dt);
                return dt;
            }
            catch (Exception)
            {
                return null;
            }
           
        }
        /// <summary>
        /// update data
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public int IDP(string sql)
        {
            try
            {
                MySqlCommand mycmd = new MySqlCommand(sql, mycon);
                return mycmd.ExecuteNonQuery();
            }
            catch(Exception)
            {
                return 0;
            }
           
            
        }
        /// <summary>
        /// close the connection
        /// </summary>
        public void Colse()
        {
            if (mycon != null)
            {
                mycon.Close();
            }
        }

    }