为什么我的串口接收不到数据

Question

            SerialPort sp = new SerialPort("COM1", 9600);
            sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);
            sp.Open();
            string strCmd = "AT+CSMP=21,167,0,8\r";
            sp.Write(strCmd);
            Thread.Sleep(100);
            strCmd = "AT+CMMS=3\r";
            sp.Write(strCmd);
            Thread.Sleep(100);
            strCmd = "AT+CMGF=1\r";
            sp.Write(strCmd);
            Thread.Sleep(100);
            strCmd = "AT+CMGS=13426023512\r";
            sp.Write(strCmd);
            Thread.Sleep(100);
            strCmd = EncodingUCS2("随便") + "\x1A";
            sp.Write(strCmd);
            Thread.Sleep(10000);            string result = String.Empty;
            int size = sp.BytesToRead;
            byte[] buffer = new byte[size];
            int count = sp.Read(buffer, 0, buffer.Length);
            result = Encoding.UTF8.GetString(buffer, 0, count).Replace("\0", "");            sp.Close();int size = sp.BytesToRead;一直是0！

Answer 1

1.在sp_DataReceived设断点监听
2.串口是否有发送数据出来？
3.检查所接的串口是否是COM1?

Answer 2

strCmd = EncodingUCS2("随便") + "\x1A";
sp.Write(strCmd);
1A是什么
试试这下面再加一句
sp.Write("\r\n");

Answer 3

        private static void sp_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            lock (_lock)
            {
                Thread.Sleep(1000);
                SerialPort sp = (SerialPort)sender;
                if (sp.IsOpen)
                {
                    string result = String.Empty;
                    byte[] buffer = new byte[128];
                    int count = sp.Read(buffer, 0, buffer.Length);
                    result = Encoding.UTF8.GetString(buffer, 0, count);
                    if (result.ToUpper().IndexOf("+CMTI") != -1)//这是收到短信
                    {
                        result = result.Replace("\r", "").Replace("\n", "");
                        string index = result.Substring(result.IndexOf(",") + 1);
                        sp.Write("at+cmgr=" + index + "\r");
                        Thread.Sleep(1000);
                        int size = sp.BytesToRead;
                        byte[] b2 = new byte[size];
                        count = sp.Read(b2, 0, b2.Length);
                        result = Encoding.UTF8.GetString(b2, 0, count);
                        string ucs2Text = result.Substring(result.LastIndexOf("\"") + 1);
                        if ((ucs2Text.IndexOf("ERROR") == -1 && ucs2Text.IndexOf("OK") != -1))
                        {
                            string text = ucs2Text.Replace("OK\r\n", "").Replace("\r", "").Replace("\n", "");
                            Console.Write("收到短信：" + DecodingUCS2(text) + Environment.NewLine);
                            sp.Write("at+cmgd=" + index + "\r");
                            Thread.Sleep(100);
                        }
                    }
                }
            }
        }接收短信的能收到

Answer 4

发送短信是用ctrl+z，不是回车

Answer 5

我被这问题搞死了，read试过了，readexisting试过了，就是收不到返回值！但是接收短信是可以的

Answer 6

你注册了DataReceived事件？那你这等的时候有没有先注销DataReceived？不注销的话，你等的这10秒时间，DataReceived事件中就先吧数据读走了。你当然没数据？

Answer 7

try
{
    注销事件
    你顶上那一段代码，
}
finally
{
    重新注册事件
}

Answer 8

果然是因为注册了DataReceived事件。