C#serialport读不到ReadLine值（串口通信）

[小人物扫雷]

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

namespace MyWinCETest
{
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}

public void InitCom(string portName)
{
serialPort1 = new SerialPort(portName, 9600, Parity.None, 8, StopBits.One);
serialPort1.ReceivedBytesThreshold = 4;
serialPort1.Handshake = Handshake.None;
serialPort1.RtsEnable = true;
serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
}

private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
try
{
StringBuilder strBuilder = new StringBuilder();
while (serialPort1.BytesToRead > 0)
{
char ch = (char)serialPort1.ReadByte();
strBuilder.Append(ch);
}
strBuilder = new StringBuilder();
}
catch (Exception ex)
{
Console.Write(ex.Message.ToString());
}
}

private void button1_Click(object sender, EventArgs e)
{
InitCom("COM1");
if (!serialPort1.IsOpen)
serialPort1.Open();
//byte[] writeBuffer = Encoding.ASCII.GetBytes(txtSend.Text.ToString());
//string strCom = Convert.ToBase64String(writeBuffer);
SendStrData(txtSend.Text.ToString());
ReceiveStrData();
}

public void SendStrData(string strCom)
{
byte[] writeBuffer = Encoding.ASCII.GetBytes(strCom);
//serialPort1.Write(writeBuffer, 0, serialPort1.BytesToWrite);
serialPort1.Write(writeBuffer, 0, writeBuffer.Length);
//serialPort1.WriteLine(strCom);
Thread.Sleep(2000);
if (serialPort1.BytesToWrite > 0)
MessageBox.Show("Data send succeed");
else MessageBox.Show("Data send failure");
}

public void ReceiveStrData()
{
if (serialPort1.BytesToRead > 0)
{
byte[] data = Convert.FromBase64String(serialPort1.ReadLine());
//byte[] data = new byte[serialPort1.ReadByte()];
txtReceive.Text = Encoding.ASCII.GetString(data, 0, data.Length);
if (serialPort1.IsOpen)
serialPort1.Close();
MessageBox.Show("Data send succeed");
}
else txtReceive.Text = "Data send failure";
}

private void button2_Click(object sender, EventArgs e)
{
string[] ports = SerialPort.GetPortNames();
Console.WriteLine("The following serial ports were found:");

// Display each port name to the console.
foreach (string port in ports)
{
Console.WriteLine(port);
}
Console.ReadLine();
}
}
}

小弟是新手，今天刚刚装了WinCE6.0，现在测试下，我读到的serialPort1.BytesToRead 和serialPort1.BytesToWrite 值都=0，而程序运行到这里就断开了。不知道怎么回事，请高人赐教。QQ：596516940

[TTOJJ]

错误提示是什么??

[yunhaiC QQ654777694]

循环读出，数据放入文本查看规律

[tigerii]

http://blog.csdn.net/tigerii/archive/2009/08/18/4460292.aspx

[小人物扫雷]

我把编译好的程序，拷贝到另一台电脑上，而且我把两台电脑的串口用线连接起来（就是连接打印机的线），结果这样也不显示发送出去的数据。

[风之影子]

你得先确定你是否成功发送数据到串口,并用串口调试助手看看是否可以成功收到.

接下来再调试你的代码.

[小人物扫雷]

没有任何错误提示，当程序单步调试到下面红色字体时就结束运行啦。serialPort1.BytesToRead 的值一直是0，不知道为什么。
public void ReceiveStrData()
{
if (serialPort1.BytesToRead > 0) {
byte[] data = Convert.FromBase64String(serialPort1.ReadLine()); //byte[] data = new byte[serialPort1.ReadByte()];
txtReceive.Text = Encoding.ASCII.GetString(data, 0, data.Length);
if (serialPort1.IsOpen)
serialPort1.Close();
MessageBox.Show("Data send succeed");
}
else txtReceive.Text = "Data send failure";
}

[mjp1234airen4385]

也许发的指令不正确，或设备没有连接。

[风之影子]

[Quote=引用 5 楼 mjp1234airen4385 的回复:]
也许发的指令不正确，或设备没有连接。
[/Quote]


排除上面的.
用下面的来读吧
byte[] data = new byte[this.serialPort1.BytesToRead];

[风之影子]

先不要加判断

[小人物扫雷]

我是在本机上用模拟器弄的。
我用SerialPort.GetPortNames()读出只有COM1这个端口号，
引用六楼的方法还是不行啊，读到这一步时就结束啦
byte[] data = new byte[this.serialPort1.BytesToRead];
还有一种疑问是不是我的数据根本就没有读到serialPort串口中啊？

[风之影子]

还有一种疑问是不是我的数据根本就没有读到serialPort串口中啊？

没有数据是不会触发DataReceived事件

你读的代码是不是放在DataReceived事件里写了

[vbdotnet2001]

放到循环中读取

[小人物扫雷]

serialPort1.Write(writeBuffer, 0, writeBuffer.Length);
或者是用serialPort1.WriteLine(Str);都发现没有值在串口中唉。
请你看下面的这些代码：

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

namespace MyWinCETest
{
    public partial class Form4 : Form
    {
        public Form4()
        {
            InitializeComponent();
        }

        public void IninCom(string portName)
        {
            serialPort1 = new SerialPort(portName, 19200, Parity.None, 8, StopBits.One);
            serialPort1.WriteTimeout = SerialPort.InfiniteTimeout;
            serialPort1.ReadTimeout = SerialPort.InfiniteTimeout;
            serialPort1.Handshake = Handshake.None;
            serialPort1.RtsEnable = true;
            serialPort1.DtrEnable = true;
            //需要接收到几个字符触发一次DataReceived的时候，ReceivedBytesThreshold就设置为几
            serialPort1.ReceivedBytesThreshold = 1;
            //serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                if (serialPort1.IsOpen)
                    serialPort1.Close();
                IninCom("COM1");
                serialPort1.Open();
                if (textBox1.Text.Trim() == "")
                {
                    MessageBox.Show("Input null!");
                    return;
                }
                byte[] data = Encoding.Default.GetBytes(textBox1.Text.Trim());
                serialPort1.Write(data, 0, data.Length);
                serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        }

        private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            byte[] data = new byte[serialPort1.ReadBufferSize];
            serialPort1.Read(data, 0, data.Length);
            string str = Encoding.Default.GetString(data, 0, data.Length);
            PortInvoke(str);
        }
        private void PortInvoke(string text)
        {
            textBox2.Invoke(new EventHandler(delegate { textBox2.Text = text; }));
        }
    }
}

就是很简单的一个界面一个Send按钮、textBox1和textBox2，实现textBox1中数据显示在textBox2中。为何就那么难显示的啊!

[风之影子]

把你下面的这行代码放在类的构造方法中
serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);



public Form4()
{
InitializeComponent();
serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
}

[小人物扫雷]

你不是说：
（没有数据是不会触发DataReceived事件，你读的代码是不是放在DataReceived事件里写了）
可是那样子的话，还是没有数据啊。

[风之影子]

你先用串口调试程序看看你下面是否有数据上来.

[小人物扫雷]

谢谢你，已经搞好了。

[mykees]

兄弟，你搞定了，能否发个完整的过来呀，我这边搞不定呀，谢了

[mykees]

有谁在线，帮下忙呀

[jin369xiaoli]

现在也在为关于串口的问题烦恼