C#串口通信 能发数据但接收不到数据 怎么回事？

[lhllucky]

刚学C#串口编程，从网上下了几个例子测试，但都是能发数据而接收不到数据，代码应该没什么问题，用一台电脑测试的，串口2，3脚串联了，就是接收不到数据，郁闷，哪位高手知道的请帮帮忙吧，谢啦！

[hongqi162]

using System.IO.Ports;
using System.Threading;
using System.IO;

namespace SerialPortDemo
{
    public partial class Form1 : Form
    {
        bool isStar = false;
        Thread threadReceive = null;
        SerialPort serialPort = null;
        int i = 0;
        int k = 0;

        public Form1()
        {
            InitializeComponent();
            this.comboBox1.SelectedIndex = 0;
            this.comboBox2.SelectedIndex = 2;

            serialPort = new SerialPort();
            if (serialPort.IsOpen)
                serialPort.Close();
            //获得参数
            serialPort.PortName = comboBox1.SelectedItem.ToString();
            serialPort.BaudRate = int.Parse(comboBox2.SelectedItem.ToString());
            serialPort.Open();

            ThreadStart method = new ThreadStart(ReceiveData);//在线程上执行此方法
            threadReceive = new Thread(new ThreadStart(method));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                if (button1.Text == "接收数据")
                {
                    if (!isStar)//如果isStar等于true,则启动线程
                    {
                        threadReceive.Start();
                        this.toolStripStatusLabel1.Text = "正在接收数据......";
                    }
                    else
                    {
                        threadReceive.Resume();//如果isStar等于false,则解除挂起线程
                        this.toolStripStatusLabel1.Text = "暂停接收...";
                    }
                    button1.Text = "停止接收";
                }
                else
                {

                    threadReceive.Suspend();//如果是"停止接收",则挂起线程
                    button1.Text = "接收数据";
                    this.toolStripStatusLabel1.Text = "暂停接收...";
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                serialPort.Close();

            }

        }
        //不断循环接收数据
        private void ReceiveData()
        {
            while (true)
            {
                Thread.Sleep(500);
                this.isStar = true;
                this.SynReceiveData();
            }
        }

        //通过串口取数据
        private void SynReceiveData()
        {
            MessageBox.Show("接收数据" + k);
            k++;
            string inputData = serialPort.ReadExisting();
            try
            {
                if (inputData != string.Empty)
                {
                    if (inputData.Trim().Length == 45)
                    {
                        SetText(inputData);
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }

        //分隔字符串并保存在指定目录下
        private void SetText(string str)
        {
            string aa = str;
            StreamWriter sw = null;

            if (aa != string.Empty)
            {
                string aaa = aa.Insert(13, ",");
                aaa = aaa.Insert(32, ",");

                String fileName = "C:\\GAJ_PUB\\kaoqin";
                if (Directory.Exists(fileName) == false)//如果目录不存在
                {
                    Directory.CreateDirectory(fileName);//创建目录
                    sw = File.CreateText("C:\\GAJ_PUB\\kaoqin\\person" + i + ".txt");//创建文本
                }
                else
                {
                    sw = File.CreateText("C:\\GAJ_PUB\\kaoqin\\person" + i + ".txt");
                }
                sw.WriteLine(aaa);

                sw.Flush();

                sw.Close();
                i++;
                MessageBox.Show("文件已存入指定目录下!!");
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (threadReceive.ThreadState==ThreadState.Running)//当前状态为启动线程
            {
                threadReceive.Abort();
                this.Close();
            }
            else if (threadReceive.ThreadState == ThreadState.Suspended)//当前状态为挂起线程
            {
                threadReceive.Resume();
                threadReceive.Abort();
                this.Close();
            }
            else if (threadReceive.ThreadState == ThreadState.SuspendRequested)//当前状态为正在挂起线程
            {
                threadReceive.Resume();
                threadReceive.Abort();
                this.Close();
            }
            else if (threadReceive.ThreadState == ThreadState.Unstarted)
            {
                this.Close();
            }
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (threadReceive.ThreadState == ThreadState.Running)//当前状态为启动线程
            {
                threadReceive.Abort();
                this.Close();
            }
            else if (threadReceive.ThreadState == ThreadState.Suspended)//当前状态为挂起线程
            {
                threadReceive.Resume();
                threadReceive.Abort();
                this.Close();
            }
            else if (threadReceive.ThreadState == ThreadState.SuspendRequested)//当前状态为正在挂起线程
            {
                threadReceive.Resume();
                threadReceive.Abort();
                this.Close();
            }
        }

       
    }
}

[gongkexin]

既然你说能发出数据，为什么23对连后会收不到数据呢，你可以用串口调试工具检测你的com口，查看是否真的你发出了数据

[lhllucky]

楼上的能不能把源码发给我啊，邮箱 [e-mail],谢了

[wdgphc]

你同一个串口的2,3脚连上后,只能打开一次串口.
但是,你没用收到数据,怎么能确认发出了呢?

[slimfeng]

你先用串口调试助手（如果没有，从网上下一个）测试一下，互发数据，如果有问题可能串口有问题，如果没有问题再查程序

[jacketl]

一楼的代码？

[gongkexin]

有一个串口调试工具 accessport133 可以在不打开com口的情况下监视你发出和收到的信息
可以去试试看

[gongkexin]

代码我没有的，因为我没遇到过这样的问题，一半23角对连是用来测试线是否有问题的

[lhllucky]

我用串口调试工具试了，也没收到，是哪的问题啊

[oneatree]

应该是 机器上还有其他的模拟串口打开了 所以接受数据的串口号可能不对

[gongkexin]

如果你所说的是事实，你可以先检查你指定的com口，如果com口没问题 你可以换根线了

[lhllucky]

谢谢大家的建议，可能是线没连接好的问题了，呵呵，怎么分啊，分太少了