c#调用oracle存储过程报错：参数类型或个数不正确，求各位大大解惑

Question

存储过程代码
create or replace procedure add_readers(i_rname    in readers.rname%type,
                                        i_ridcard  in readers.ridcard%type,
                                        i_rsex     in readers.rsex%type,
                                        i_runit    in readers.runit%type,
                                        i_radd     in readers.radd%type,
                                        i_rphone   in readers.rphone%type,
                                        o_result   out number)
                                        as
  o_readers  number;
begin
  o_result:=0;
  select count(*)
    into o_readers
    from readers a
   where rname = i_rname
     and ridcard = i_ridcard;
  if o_readers < 1 then
    insert into readers
      (rid, rname, ridcard, rsex, runit, radd, rphone, rregdate)
    values
      (SEQ_READERS.NEXTVAL,
       i_rname,
       i_ridcard,
       i_rsex,
       i_runit,
       i_radd,
       i_rphone,
       sysdate);
    commit;
/*    dbms_output.put_line('插入成功！');*/
    o_result:=1;
  else
    update readers a
       set a.rstate=''
     where a.rname = i_rname
       and a.ridcard = i_ridcard;
    commit;
/*    dbms_output.put_line('该读者已存在！并重新激活');*/
    o_result:=2;
  end if;
  dbms_output.put_line(o_result);
end add_readers;
c#代码：
        private void but_submit_Click(object sender, EventArgs e)
        {
            string  sex;
            decimal result = 0;
            if (radio_man.Checked == true)
            {
                sex = "男";
            }
            else 
            {
                sex = "女";
            }
            if (name_box.Text.Length > 0 && idcard_box.Text.Length > 0 && adress_box.Text.Length > 0 && uint_box.Text.Length > 0 && phone_box.Text.Length > 0)
            {
                OracleConnection conn = new OracleConnection("Data Source=ORCL;User ID=HJR;Password=HJR;Unicode=True");
                OracleCommand cmd = new OracleCommand("add_readers", conn);
                cmd.CommandType = CommandType.StoredProcedure;//指明是执行存储过程
                OracleParameter[] parm = new OracleParameter[7];
                //in
                parm[0] = new OracleParameter("i_rname", OracleType.VarChar,255);   //与SQL区别,sql存储过程需要在定义与此处,在其参数前加"@"符号;
                parm[1] = new OracleParameter("i_ridcard", OracleType.VarChar,255);
                parm[2] = new OracleParameter("i_rsex", OracleType.VarChar, 255);
                parm[3] = new OracleParameter("i_runit", OracleType.VarChar,255);
                parm[4] = new OracleParameter("i_radd", OracleType.VarChar,255);
                parm[5] = new OracleParameter("i_rphone", OracleType.VarChar,255);
                //out
                parm[6] = new OracleParameter("o_result", OracleType.Number);
                //指明参数是输入还是输出型
                parm[0].Direction = ParameterDirection.Input;
                parm[1].Direction = ParameterDirection.Input;
                parm[2].Direction = ParameterDirection.Input;
                parm[3].Direction = ParameterDirection.Input;
                parm[4].Direction = ParameterDirection.Input;
                parm[5].Direction = ParameterDirection.Input;
                parm[6].Direction = ParameterDirection.Output;
                parm[0].Value = name_box.Text.Trim();
                parm[1].Value = sex;
                parm[2].Value = idcard_box.Text.Trim();
                parm[3].Value = uint_box.Text.Trim();
                parm[4].Value = adress_box.Text.Trim();
                parm[5].Value = phone_box.Text.Trim();
                try
                {
                    conn.Open();
                    int i = cmd.ExecuteNonQuery();
                    /*result = (decimal)cmd.Parameters["o_result"].Value;*/
                    result = Convert.ToDecimal(parm[6].Value);
                }
                catch (OracleException ex)
                {
                    MessageBox.Show(ex.ToString());
                }
                finally
                {
                    if (cmd.Connection.State == ConnectionState.Open)
                    {
                        cmd.Connection.Close();
                        cmd.Connection.Dispose();
                        cmd.Parameters.Clear();
                        cmd.Dispose();
                    }
                    //return result;
                }
                if (result == 1)
                {
                    MessageBox.Show("新增读者成功！");
                }
                else if (result == 2)
                {
                    MessageBox.Show("该读者已存在并激活！");
                }
                else
                {
                    MessageBox.Show("新增读者失败！");
                }
             }
            else
            {
                MessageBox.Show("请填写完整信息！");
            }
        }
各位大大能帮忙看下是那里的问题吗，本人刚接触oracle存储OracleC#错误

Answer 1

原来是我忘了把参数填加到parameter中了，在try前面加                foreach (OracleParameter parameter in parm)
                {
                    cmd.Parameters.Add(parameter);
                }；
希望这个低级错误供部分初学参考