c# winform 读取oracle中blob字段的图片显示到pictureBox里

private void button1_Click(object sender, EventArgs e)

 {

   OracleConnection conn = dbc.getConnection();//获得conn连接

      try {

              //重新连接数据库

                conn.Open(); 

                OracleCommand cmd = conn.CreateCommand();

                cmd.CommandText = "select xp from user_xp where id = 12345 ";//查询获得图片流

                OracleDataReader oddr = cmd.ExecuteReader();//创建一个OracleDateReader对象

              &n