SerialPort类
微软在.NET中对串口通讯进行了封装，我们可以在.net2.0及以上版本开发时直接使用SerialPort类对串口进行读写操作。
为操作方便，本文对SerialPort类做了一些封装，暂时取名为SerialPortClient。
SerialPort类的属性主要包括：
- 串口名称（PortName）
- 波特率（BaudRate）
- 数据位 DataBits
- 停止位 StopBits
- 奇偶校验 Parity
SerialPort类的事件主要包括：
- DataReceived：用于异步接收串口数据事件
- ErrorReceived：错误处理事件
SerialPort类的方法主要包括：Open();Close();Read();Write()、DiscardInBuffer()、DiscardOutBuffer()等
参数封装
波特率、数据位这些参数不是系统内置的枚举类型，为方便实际操作需构造波特率、数据位这两个枚举对象。
/// <summary>
/// 串口数据位列表（5,6,7,8）
/// </summary>
public enum DataBits : int
{
Five = 5,
Six = 6,
Sevent = 7,
Eight = 8
}
/// <summary>
/// 串口波特率列表。
/// 75,110,150,300,600,1200,2400,4800,9600,14400,19200,28800,38400,56000,57600,
/// 115200,128000,230400,256000
/// </summary>
public enum BaudRates : int
{
BR_75 = 75,
BR_110 = 110,
BR_150 = 150,
BR_300 = 300,
BR_600 = 600,
BR_1200 = 1200,
BR_2400 = 2400,
BR_4800 = 4800,
BR_9600 = 9600,
BR_14400 = 14400,
BR_19200 = 19200,
BR_28800 = 28800,
BR_38400 = 38400,
BR_56000 = 56000,
BR_57600 = 57600,
BR_115200 = 115200,
BR_128000 = 128000,
BR_230400 = 230400,
BR_256000 = 256000
}
控件操作封装
对常用的参数下拉列表绑定做一个封装，该操作为封装类的静态方法。
为兼容第三方控件使用IList接口，不直接使用ComboBox类型作为参数。
/// <summary>
/// 设置串口号
/// </summary>
/// <param name="obj">需要绑定的项的集合（如：ComboBox中项的集合ComboBox.Items）</param>
public static void SetPortNameValues(IList obj)
{
obj.Clear();
try
{
foreach (string str in SerialPort.GetPortNames())
{
obj.Add(str);
}
}
catch (Exception e)
{
Console.WriteLine("未能查询到串口名称——"+e.ToString());
}
}
/// <summary>
/// 设置波特率
/// </summary>
/// <param name="obj">需要绑定的项的集合（如：ComboBox中项的集合ComboBox.Items）</param>
public static void SetBauRateValues(IList obj)
{
obj.Clear();
foreach (BaudRates rate in Enum.GetValues(typeof(BaudRates)))
{
obj.Add(((int)rate).ToString());
}
}
/// <summary>
/// 设置数据位
/// </summary>
/// <param name="obj">需要绑定的项的集合（如：ComboBox中项的集合ComboBox.Items）</param>
public static void SetDataBitsValues(IList obj)
{
obj.Clear();
foreach (DataBits databit in Enum.GetValues(typeof(DataBits)))
{
obj.Add(((int)databit).ToString());
}
}
/// <summary>
/// 设置校验位列表
/// </summary>
/// <param name="obj">需要绑定的项的集合（如：ComboBox中项的集合ComboBox.Items）</param>
public static void SetParityValues(IList obj)
{
obj.Clear();
foreach (string str in Enum.GetNames(typeof(Parity)))
{
obj.Add(str);
}
}
/// <summary>
/// 设置停止位
/// </summary>
/// <param name="obj">需要绑定的项的集合（如：ComboBox中项的集合ComboBox.Items）</param>
public static void SetStopBitValues(IList obj)
{
obj.Clear();
foreach (string str in Enum.GetNames(typeof(StopBits)))
{
obj.Add(str);
}
}
SerialPortClient类实现
该部分代码是SerialPortClient类非静态操作部分的实现，完整的类实现需要加上上面的控件操作封装的实现代码，具体请参照Demo源码。
public event Action<List<byte>> DataReceived;
public event SerialErrorReceivedEventHandler ErrorReceived;
private SerialPort comPort = new SerialPort();
private string portName = "COM1";//串口号，默认COM1
private BaudRates baudRate = BaudRates.BR_9600;//波特率
private Parity parity = Parity.None;//校验位
private StopBits stopBits = StopBits.One;//停止位
private DataBits dataBits = DataBits.Eight;//数据位
/// <summary>
/// 串口号
/// </summary>
public string PortName
{
get { return portName; }
set { portName = value; }
}
/// <summary>
/// 波特率
/// </summary>
public BaudRates BaudRate
{
get { return baudRate; }
set { baudRate = value; }
}
/// <summary>
/// 奇偶校验位
/// </summary>
public Parity Parity
{
get { return parity; }
set { parity = value; }
}
/// <summary>
/// 数据位
/// </summary>
public DataBits DataBits
{
get { return dataBits; }
set { dataBits = value; }
}
/// <summary>
/// 停止位
/// </summary>
public StopBits StopBits
{
get { return stopBits; }
set { stopBits = value; }
}
/// <summary>
/// 无参构造函数
/// </summary>
public SerialPortClient()
{
BoundEvents();
}
void BoundEvents()
{
comPort.DataReceived += new SerialDataReceivedEventHandler(comPort_DataReceived);
comPort.ErrorReceived += new SerialErrorReceivedEventHandler(comPort_ErrorReceived);
}
/// <summary>
/// 参数构造函数（使用枚举参数构造）
/// </summary>
/// <param name="baud">波特率</param>
/// <param name="par">奇偶校验位</param>
/// <param name="sBits">停止位</param>
/// <param name="dBits">数据位</param>
/// <param name="name">串口号</param>
public SerialPortClient(string name, BaudRates baud, Parity par, DataBits dBits, StopBits sBits)
{
this.portName = name;
this.baudRate = baud;
this.parity = par;
this.dataBits = dBits;
this.stopBits = sBits;
BoundEvents();
}
/// <summary>
/// 参数构造函数（使用字符串参数构造）
/// </summary>
/// <param name="baud">波特率</param>
/// <param name="par">奇偶校验位</param>
/// <param name="sBits">停止位</param>
/// <param name="dBits">数据位</param>
/// <param name="name">串口号</param>
public SerialPortClient(string name, string baud, string par, string dBits, string sBits)
{
this.portName = name;
this.baudRate = (BaudRates)Enum.Parse(typeof(BaudRates), baud);
this.parity = (Parity)Enum.Parse(typeof(Parity), par);
this.dataBits = (DataBits)Enum.Parse(typeof(DataBits), dBits);
this.stopBits = (StopBits)Enum.Parse(typeof(StopBits), sBits);
BoundEvents();
}
/// <summary>
/// 数据仓库
/// </summary>
List<byte> datapool = new List<byte>();//存放接收的所有字节
/// <summary>
/// 数据接收处理
/// </summary>
void comPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
if (comPort.IsOpen) //判断是否打开串口
{
Byte[] receivedData = new Byte[comPort.BytesToRead]; //创建接收字节数组
comPort.Read(receivedData, 0, receivedData.Length); //读取数据
//触发整条记录的处理
if (DataReceived != null)
{
datapool.AddRange(receivedData);
DataReceived(datapool);
}
}
else
{
Console.WriteLine("请打开某个串口", "Error");
}
}
/// <summary>
/// 错误处理函数
/// </summary>
void comPort_ErrorReceived(object sender, SerialErrorReceivedEventArgs e)
{
if (ErrorReceived != null)
{
ErrorReceived(sender, e);
}
}
/// <summary>
/// 端口是否已经打开
/// </summary>
public bool IsOpen
{
get
{
return comPort.IsOpen;
}
}
/// <summary>
/// 打开端口
/// </summary>
/// <returns></returns>
public void Open()
{
if (comPort.IsOpen) comPort.Close();
comPort.PortName = portName;
comPort.BaudRate = (int)baudRate;
comPort.Parity = parity;
comPort.DataBits = (int)dataBits;
comPort.StopBits = stopBits;
comPort.Open();
}
/// <summary>
/// 关闭端口
/// </summary>
public void Close()
{
if (comPort.IsOpen) comPort.Close();
}
/// <summary>
/// 丢弃来自串行驱动程序的接收和发送缓冲区的数据
/// </summary>
public void DiscardBuffer()
{
comPort.DiscardInBuffer();
comPort.DiscardOutBuffer();
}
/// <summary>
/// 写入数据
/// </summary>
/// <param name="buffer"></param>
public void Write(byte[] buffer, int offset, int count)
{
if (!(comPort.IsOpen)) comPort.Open();
comPort.Write(buffer,offset, count);
}
/// <summary>
/// 写入数据
/// </summary>
/// <param name="buffer">写入端口的字节数组</param>
public void Write(byte[] buffer)
{
if (!(comPort.IsOpen)) comPort.Open();
comPort.Write(buffer, 0, buffer.Length);
}
SerialPortClient类使用
SerialPortClient类使用很简单，主要分为初始化下拉列表、初始化串口（绑定数据接收、错误处理事件）两步，在窗体加载事件中调用即可。代码如下：
//全局变量
SerialPortClient portClient = new SerialPortClient();
private void InitPort()
{
portClient.DataReceived+=new Action<List<byte>>(datapool=>
{
//匹配数据帧，此处以0xea 0xeb为帧头、0xfa 0xfb为帧尾
//实际通讯协议应该更复杂
while (true)
{
if (datapool.Count <4) break;
if ((datapool[0] == 0xea) && (datapool[0] == 0xeb))
{
datapool.RemoveAt(0);
continue;
}
int index = -1;//正确作法是记住上次最末尾的索引，避免重复匹配
for (int i = 0; i < datapool.Count-1; i++)
{
if (datapool[i] == 0xfa && datapool[i + 1] == 0xfb)
{
index = i;
break;
}
}
if (index != -1)
{
byte[] data = datapool.GetRange(0, index + 2).ToArray();
datapool.RemoveRange(0, index + 2);
string msg = Encoding.UTF8.GetString(data,2,data.Length-4);
this.BeginInvoke(new Action(() => { textBox_Recive.Text = msg; }));
}
else break;
}
});
}
private void InitCmb()
{
//绑定端口号
SerialPortClient.SetPortNameValues(comboBox_Com.Items);
comboBox_Com.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox_Com.SelectedIndexChanged += new EventHandler((obj, e) =>
{
if (comboBox_Com.SelectedItem!=null)
{
portClient.PortName = comboBox_Com.SelectedItem.ToString();
}
});
comboBox_Com.SelectedIndex = 0;
//波特率
SerialPortClient.SetBauRateValues(comboBox_BaudRates.Items);
comboBox_BaudRates.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox_BaudRates.SelectedIndexChanged += new EventHandler((obj, e) =>
{
if (comboBox_BaudRates.SelectedItem != null)
{
portClient.BaudRate = (BaudRates)Enum.Parse(typeof(BaudRates), comboBox_BaudRates.SelectedItem.ToString());
}
});
comboBox_BaudRates.SelectedIndex = 9;
//数据位
SerialPortClient.SetDataBitsValues(comboBox_DataBits.Items);
comboBox_DataBits.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox_DataBits.SelectedIndexChanged += new EventHandler((obj, e) =>
{
if (comboBox_DataBits.SelectedItem != null)
{
portClient.DataBits = (DataBits)Enum.Parse(typeof(DataBits), comboBox_DataBits.SelectedItem.ToString());
}
});
comboBox_DataBits.SelectedIndex = 3;
//校验位
SerialPortClient.SetParityValues(comboBox_Parity.Items);
comboBox_Parity.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox_Parity.SelectedIndexChanged += new EventHandler((obj, e) =>
{
if (comboBox_Parity.SelectedItem != null)
{
portClient.Parity = (Parity)Enum.Parse(typeof(Parity), comboBox_Parity.SelectedItem.ToString());
}
});
comboBox_Parity.SelectedIndex = 0;
//停止位
SerialPortClient.SetStopBitValues(comboBox_StopBits.Items);
comboBox_StopBits.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox_StopBits.SelectedIndexChanged += new EventHandler((obj, e) =>
{
if (comboBox_StopBits.SelectedItem != null)
{
portClient.StopBits = (StopBits)Enum.Parse(typeof(StopBits), comboBox_StopBits.SelectedItem.ToString());
}
});
comboBox_StopBits.SelectedIndex = 1;
}
串口的打开、关闭、状态显示等操作请查看文章末尾的Demo源码。
测试Demo
