C# 读取AT命令结果代码

我正在做一个项目，其中包括向手机调制解调器发送

AT

命令并接收结果代码。 我已经成功地发送了at命令，但我无法理解的是从命令中读取结果代码，例如当您发送“at”时，它返回“OK”，如果您发送“at+cbc”，它返回电池状态。 在发送命令后，我尝试使用Read、ReadLine和ReadExisting，但不起作用，我还尝试为接收到的数据创建事件并使用这些函数，但也不起作用。 这是我的源代码，希望你能给我一些帮助

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;

namespace WindowsFormsApplication1
{
    public partial class check : Form
    {
        SerialPort sp;

        public check()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            sp = new SerialPort();
            sp.PortName = "COM3";
            sp.BaudRate = 9600;
            sp.Parity = Parity.None;
            sp.DataBits = 8;
            sp.StopBits = StopBits.One;
            sp.ReadTimeout = 3000;
            sp.WriteTimeout = 3000;
            //sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);
        }

        private void btn1_Click(object sender, EventArgs e)
        {
            try
            {
                if(!sp.IsOpen)
                {
                    sp.Open();
                }
                sp.WriteLine(tbCmd+"\r\n");
                System.Threading.Thread.Sleep(2000);
                tbStatus.Text = sp.ReadLine();      
            }
            catch(Exception ex)
            {
                tbStatus.Text = "Error!\r\n" + ex.ToString();
            }
        }

        //void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
        //{
        //    tbStatus.Text = sp.ReadExisting();
        //}
    }
}

---

我在诺基亚论坛上看到，诺基亚60系列手机不支持阅读短信命令，而此at命令在诺基亚手机上不起作用

@motevallizadeh:可能是包含应通过COM端口发送的at命令的文本框。。。

    sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);

    void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        if(e.EventType != SerialData.Chars)
        {
            tbStatus.Text = "IGNORED: " + e.EventType.ToString();
            return;
        }
        try
        {
            int nBytesToRead = sp.BytesToRead;
            char[] receivedData = new char[nBytesToRead];
            sp.Read(receivedData, 0, nBytesToRead);
            tbStatus.Text = "RECEIVED: " + new string(receivedData);
        }
        catch (Exception ex)
        {
            tbStatus.Text = "ERROR: " + ex.Message;
        }
    }