串口通信基本知识及实例开发2（Com口通信开发实例）

素颜马尾好姑娘i 2022-10-26 14:25 240阅读 0赞

上一篇讲的是Com通信的基本知识，这一篇讲一下Com开发实例

首先，找一个com头，有公母之分，现在一般都是Usb转Com的，短接一下Com头的2(接收pin)/3(发送pin),然后就可以进行测试了

在短接的时候注意一下别短接错了,使用winform做出如下的界面

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NkYzg1OTY_size_16_color_FFFFFF_t_70][]

1.定义一个SerialPort

private SerialPort ComDevice=new SerialPort();

2.Load初始化及接收数据的方法

private void Form_Load(object sender,EventArgs e)
    {
        //获取主机所有的COM口
        cmbCom.Items.AddRange(SerialPort.GetPortNames());
        if(cmbCom.Items.Count>0)
        {
            cmbCom.SelectedIndex=0;
        }
        cmbBaudRate.SelectedIndex=5;
        cmbDataBits.SelectedIndex=0;
        cmbCheck.SelectedIndex=0;
        cmbStopBits.SelectedIndex=0;
        //给DataReceived事件注册数据接收方法
        ComDevice.DataReceived+=new SerialDataReceivedEventHandler(Com_DataReceived);
    }
    
    //接收数据
    private void Com_DataReceived(object sender,SerialDataReceivedEventArgs e)
    {
        byte[] ReDatas=new byte[ComDevice.BytesToRead];
        //读取数据
        ComDevice.Read(ReDatas,0,ReDatas.Length);
        //输出数据
        AddData(ReDatas);
    }
    //根据选择的格式进行转换
    private void AddData(byte[] reDatas)
    {
        if(rbtnHexReceive.Checked)
        {
            StringBuilder sb=new StringBuilder();
            for(int i=0;i<reDatas.Length;i++)
            {
                sb.AppendFormat("{0:x2}"+" ",reDatas[i]);
            }
            AddContent(sb.ToString().ToUpper());
        }
        else if(rbtnAscReceive.Checked)
        {
            AddContent(new ASCIIEncoding().GetString(reDatas));    
        }
        else if(rbtnUTFReceive.Checked)
        {
            AddContent(new UTF8Encoding().GetString(reDatas));
        }
        else if(rbtnUnicodeReceive.Checked)
        {
            AddContent(new UnicodeEncoding().GetString(reDatas));
        }
        txtReceiveCount.Invoke(new MethodInvoker(delegate
        {
            txtReceiveCount.Text=(int.Parse(txtReceiveCount.Text)+reDatas.Length).ToString();
        }));
    }
    
    
    //委托执行控件信息
    privte void AddContent(string content)
    {
        this.Invoke(new MethodInvoker(delegate
        {
            txtReceiveData.AppendText(content);
        }));
    }

3.打开Com口

private void btnOpenCom_Click(object sender,Eventargs e)
    {
        if(cmbCom.Items.Count<1)
        {
            MessageBox.Show("没有发现串口");
            return;
        }
        if(ComDevice.IsOpen==false)
        {
            ComDevice.PortName=cmbCom.SelectedItem.ToString();
            ComDevice.BaudRate=Convert.ToInt32(cmbBaudRate.SelectedItem.ToString());
            ComDevice.Parity=(Parity)Convert.ToInt32(cmbCheck.SelectedIndex.ToString());
            ComDevice.DataBits=Convert.ToInt32(cmbDataBits.SelectedItem.ToString());
            ComDevice.StopBits=(StopBits)Convert.ToInt32(cmbStopBits.SelectedItem.ToString());
            try
            {
                ComDevice.Open();
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message,"error");
            }
        }
        else
        {
            try
            {
                ComDevice.Close();
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message,"error");
            }
        }
    }

4.发送数据

//串口发送数据
    private bool SendData(byte[] data)
    {
        try
        {
            if(ComDevice.IsOpen)
            {
                ComDevice.Write(data,0,data.Length);
                return true;
            }
            else
            {
                MessageBox.Show("串口未打开");
                return false;
            }
        }
        catch(Exception ex)
        {
            MessageBox.Show(ex.Message);
            return false;
        }
    }
    //点击发送数据的动作
    private void btnSend_Click(object sender,EventArgs e)
    {
          byte[] sendData=null;
          if(rbtnHexSend.Checked)
            {
                sendData=strtoHexByte(txtSendData.Text.Trim());
            }
            else if(rbtnAscSend.Checked)
            {
                sendData=Encoding.ASCII.GetBytes(txtSendData.Text.Trim());
            }
             else if(rbtnUTFSend.Checked)
            {
                sendData=Encoding.UTF8.GetBytes(txtSendData.Text.Trim());
            }
             else if(rbtnUnicodeSend.Checked)
            {
                sendData=Encoding.Unicode.GetBytes(txtSendData.Text.Trim());
            }
             else
            {
                sendData=Encoding.ASCII.GetBytes(txtSendData.Text.Trim());
            }
             //发送数据
            if(this.SendData(sendData))
            {
                txtSendCount.Invoke(new MethodInvoker(delegate
                {
                    txtSendCount.Text=(int.Parse(txtSendCount.Text)+txtSendData.Text.Length).ToString();
                }));
            }
            else
            {
                ;
            }
        
    }
    
    //字符串转换为16进制的数组
    private byte[] strtoHexByte(string hexString)
    {
        hexString=hexString.Replace(" ","");
        if(hexString.Length%2!=0)
        {
            hexString+=" ";
        }
        byte[] returnBytes=new Byte[hexString.Length/2];
        for(int i=0;i<returnBytes.Length;i++)
        {
            returnBytes[i]=Convert.ToByte(hexString.Substring(i*2,2).Replace(" ",""),16);
        }
        return returnBytes;
    }

5.清空的动作

private void btnClearReceiveArea_Click(object sender,EventArgs e)
    {
        txtReceiveData.Clear();
    }
    
    private void btnClearSendArea_Click(object sender,EventArgs e)
    {
        txtSendData.CLear();
    }

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