c# 串口操作

public class CommPort : IDisposable
{
public string Port = "";
///<summary>
///波特率9600
///</summary>
private int BaudRate = 9600;

public int BaudRater
{
set { BaudRate = value; }
}
///<summary>
///数据位4-8
///</summary>
public byte ByteSize = 8; //4-8
///<summary>
///奇偶校验0-4=no,odd,even,mark,space
///</summary>
public byte Parity = 0; //0-4=no,odd,even,mark,space
///<summary>
///停止位
///</summary>
public byte StopBits = 0; //0,1,2 = 1, 1.5, 2
///<summary>
///超时长
///</summary>
private int ReadTimeout = 200;

public int ReadTimeouter
{
set { ReadTimeout = value; }
}
///<summary>
///串口是否已经打开
///</summary>
public bool Opened = false;
///<summary>
/// COM口句柄
///</summary>
private int hComm = -1;

#region "API相关定义"
private const string DLLPATH = "kernel32";

///<summary>
/// WINAPI常量,写标志
///</summary>
private const uint GENERIC_READ = 0x80000000;
///<summary>
/// WINAPI常量,读标志
///</summary>
private const uint GENERIC_WRITE = 0x40000000;
///<summary>
/// WINAPI常量,打开已存在
///</summary>
private const int OPEN_EXISTING = 3;
///<summary>
/// WINAPI常量,无效句柄
///</summary>
private const int INVALID_HANDLE_VALUE = -1;

private const int PURGE_RXABORT = 0x2;
private const int PURGE_RXCLEAR = 0x8;
private const int PURGE_TXABORT = 0x1;
private const int PURGE_TXCLEAR = 0x4;

///<summary>
///设备控制块结构体类型
///</summary>
[StructLayout(LayoutKind.Sequential)]
public struct DCB
{
///<summary>
/// DCB长度
///</summary>
public int DCBlength;
///<summary>
///指定当前波特率
///</summary>
public int BaudRate;
///<summary>
///标志位
///</summary>
public uint flags;
///<summary>
///未使用,必须为0
///</summary>
public ushort wReserved;
///<summary>
///指定在XON字符发送这前接收缓冲区中可允许的最小字节数
///</summary>
public ushort XonLim;
///<summary>
///指定在XOFF字符发送这前接收缓冲区中可允许的最小字节数
///</summary>
public ushort XoffLim;
///<summary>
///指定端口当前使用的数据位
///</summary>
public byte ByteSize;
///<summary>
///指定端口当前使用的奇偶校验方法,可能为:EVENPARITY,MARKPARITY,NOPARITY,ODDPARITY 0-4=no,odd,even,mark,space
///</summary>
public byte Parity;
///<summary>
///指定端口当前使用的停止位数,可能为:ONESTOPBIT,ONE5STOPBITS,TWOSTOPBITS 0,1,2 = 1, 1.5, 2
///</summary>
public byte StopBits;
///<summary>
///指定用于发送和接收字符XON的值 Tx and Rx XON character
///</summary>
public byte XonChar;
///<summary>
///指定用于发送和接收字符XOFF值 Tx and Rx XOFF character
///</summary>
public byte XoffChar;
///<summary>
///本字符用来代替接收到的奇偶校验发生错误时的值
///</summary>
public byte ErrorChar;
///<summary>
///当没有使用二进制模式时,本字符可用来指示数据的结束
///</summary>
public byte EofChar;
///<summary>
///当接收到此字符时,会产生一个事件
///</summary>
public byte EvtChar;
///<summary>
///未使用
///</summary>
public ushort wReserved1;
}

///<summary>
///串口超时时间结构体类型
///</summary>
[StructLayout(LayoutKind.Sequential)]
private struct COMMTIMEOUTS
{
public int ReadIntervalTimeout;
public int ReadTotalTimeoutMultiplier;
public int ReadTotalTimeoutConstant;
public int WriteTotalTimeoutMultiplier;
public int WriteTotalTimeoutConstant;
}

///<summary>
///溢出缓冲区结构体类型
///</summary>
[StructLayout(LayoutKind.Sequential)]
private struct OVERLAPPED
{
public int Internal;
public int InternalHigh;
public int Offset;
public int OffsetHigh;
public int hEvent;
}

///<summary>
///打开串口
///</summary>
///<param name="lpFileName">要打开的串口名称</param>
///<param name="dwDesiredAccess">指定串口的访问方式，一般设置为可读可写方式</param>
///<param name="dwShareMode">指定串口的共享模式，串口不能共享，所以设置为0</param>
///<param name="lpSecurityAttributes">设置串口的安全属性，WIN9X下不支持，应设为NULL</param>
///<param name="dwCreationDisposition">对于串口通信，创建方式只能为OPEN_EXISTING</param>
///<param name="dwFlagsAndAttributes">指定串口属性与标志，设置为FILE_FLAG_OVERLAPPED(重叠I/O操作)，指定串口以异步方式通信</param>
///<param name="hTemplateFile">对于串口通信必须设置为NULL</param>
[DllImport(DLLPATH)]
private static extern int CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode,
int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);

///<summary>
///得到串口状态
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpDCB">设备控制块DCB</param>
[DllImport(DLLPATH)]
private static extern bool GetCommState(int hFile, ref DCB lpDCB);

///<summary>
///建立串口设备控制块(嵌入版没有)
///</summary>
///<param name="lpDef">设备控制字符串</param>
///<param name="lpDCB">设备控制块</param>
//[DllImport(DLLPATH)]
//private static extern bool BuildCommDCB(string lpDef, ref DCB lpDCB);

///<summary>
///设置串口状态
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpDCB">设备控制块</param>
[DllImport(DLLPATH)]
private static extern bool SetCommState(int hFile, ref DCB lpDCB);

///<summary>
///读取串口超时时间
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpCommTimeouts">超时时间</param>
[DllImport(DLLPATH)]
private static extern bool GetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts);

///<summary>
///设置串口超时时间
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpCommTimeouts">超时时间</param>
[DllImport(DLLPATH)]
private static extern bool SetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts);

///<summary>
///读取串口数据
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpBuffer">数据缓冲区</param>
///<param name="nNumberOfBytesToRead">多少字节等待读取</param>
///<param name="lpNumberOfBytesRead">读取多少字节</param>
///<param name="lpOverlapped">溢出缓冲区</param>
[DllImport(DLLPATH)]
private static extern bool ReadFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToRead,
ref int lpNumberOfBytesRead, ref OVERLAPPED lpOverlapped);

///<summary>
///写串口数据
///</summary>
///<param name="hFile">通信设备句柄</param>
///<param name="lpBuffer">数据缓冲区</param>
///<param name="nNumberOfBytesToWrite">多少字节等待写入</param>
///<param name="lpNumberOfBytesWritten">已经写入多少字节</param>
///<param name="lpOverlapped">溢出缓冲区</param>
[DllImport(DLLPATH)]
private static extern bool WriteFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToWrite,
ref int lpNumberOfBytesWritten, ref OVERLAPPED lpOverlapped);

[DllImport(DLLPATH, SetLastError = true)]
private static extern bool FlushFileBuffers(int hFile);

[DllImport(DLLPATH, SetLastError = true)]
private static extern bool PurgeComm(int hFile, uint dwFlags);

///<summary>
///关闭串口
///</summary>
///<param name="hObject">通信设备句柄</param>
[DllImport(DLLPATH)]
private static extern bool CloseHandle(int hObject);

///<summary>
///得到串口最后一次返回的错误
///</summary>
[DllImport(DLLPATH)]
private static extern uint GetLastError();
#endregion

///<summary>
///设置DCB标志位
///</summary>
///<param name="whichFlag"></param>
///<param name="setting"></param>
///<param name="dcb"></param>
internal void SetDcbFlag(int whichFlag, int setting, DCB dcb)
{
uint num;
setting = setting << whichFlag;
if ((whichFlag == 4) || (whichFlag == 12))
{
num = 3;
}
else if (whichFlag == 15)
{
num = 0x1ffff;
}
else
{
num = 1;
}
dcb.flags &= ~(num << whichFlag);
dcb.flags |= (uint)setting;
}

///<summary>
///建立与串口的连接
///</summary>
public int Open()
{
if (Port == "") return -1;
DCB dcb = new DCB();
COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();

// 打开串口
hComm = CreateFile(Port, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
if (hComm == INVALID_HANDLE_VALUE)
{
return -1;
}
// 设置通信超时时间
GetCommTimeouts(hComm, ref ctoCommPort);
ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
ctoCommPort.ReadTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutConstant = 0;
SetCommTimeouts(hComm, ref ctoCommPort);

//设置串口参数
GetCommState(hComm, ref dcb);
dcb.DCBlength = Marshal.SizeOf(dcb);
dcb.BaudRate = BaudRate;
dcb.flags = 0;
dcb.ByteSize = (byte)ByteSize;
dcb.StopBits = StopBits;
dcb.Parity = (byte)Parity;

//------------------------------
SetDcbFlag(0, 1, dcb); //二进制方式
SetDcbFlag(1, (Parity == 0) ? 0 : 1, dcb);
SetDcbFlag(2, 0, dcb); //不用CTS检测发送流控制
SetDcbFlag(3, 0, dcb); //不用DSR检测发送流控制
SetDcbFlag(4, 0, dcb); //禁止DTR流量控制
SetDcbFlag(6, 0, dcb); //对DTR信号线不敏感
SetDcbFlag(9, 1, dcb); //检测接收缓冲区
SetDcbFlag(8, 0, dcb); //不做发送字符控制
SetDcbFlag(10, 0, dcb); //是否用指定字符替换校验错的字符
SetDcbFlag(11, 0, dcb); //保留NULL字符
SetDcbFlag(12, 0, dcb); //允许RTS流量控制
SetDcbFlag(14, 0, dcb); //发送错误后，继续进行下面的读写操作
//--------------------------------
dcb.wReserved = 0; //没有使用，必须为0
dcb.XonLim = 0; //指定在XOFF字符发送之前接收到缓冲区中可允许的最小字节数
dcb.XoffLim = 0; //指定在XOFF字符发送之前缓冲区中可允许的最小可用字节数
dcb.XonChar = 0; //发送和接收的XON字符
dcb.XoffChar = 0; //发送和接收的XOFF字符
dcb.ErrorChar = 0; //代替接收到奇偶校验错误的字符
dcb.EofChar = 0; //用来表示数据的结束
dcb.EvtChar = 0; //事件字符，接收到此字符时，会产生一个事件
dcb.wReserved1 = 0; //没有使用

if (!SetCommState(hComm, ref dcb))
{
return -2;
}
Opened = true;
return 0;
}
///<summary>
///关闭串口,结束通讯
///</summary>
public void Close()
{
try
{
if (hComm != INVALID_HANDLE_VALUE)
{
CloseHandle(hComm);
}
}
catch (Exception ex)
{

}
}
///<summary>
///读取串口返回的数据
///</summary>
///<param name="NumBytes">数据长度</param>
public int Read(ref byte[] bytData, int NumBytes)
{
try
{
if (hComm != INVALID_HANDLE_VALUE)
{
OVERLAPPED ovlCommPort = new OVERLAPPED();
int BytesRead = 0;
ReadFile(hComm, bytData, NumBytes, ref BytesRead, ref ovlCommPort);
return BytesRead;
}
else
{
return -1;
}
}
catch (Exception ex)
{
LogInfo log = new LogInfo();
log.WriteLog(ex.Message);
return -1;
}
}

///<summary>
///向串口写数据
///</summary>
///<param name="WriteBytes">数据数组</param>
public int Write(byte[] WriteBytes, int intSize)
{
try
{
if (hComm != INVALID_HANDLE_VALUE)
{
OVERLAPPED ovlCommPort = new OVERLAPPED();
int BytesWritten = 0;
WriteFile(hComm, WriteBytes, intSize, ref BytesWritten, ref ovlCommPort);
return BytesWritten;
}
else
{
return -1;
}
}
catch (Exception ex)
{
LogInfo log = new LogInfo();
log.WriteLog(ex.Message);
return -1;
}
}

///<summary>
///清除接收缓冲区
///</summary>
///<returns></returns>
public void ClearReceiveBuf()
{
if (hComm != INVALID_HANDLE_VALUE)
{
PurgeComm(hComm, PURGE_RXABORT | PURGE_RXCLEAR);
}
}

///<summary>
///清除发送缓冲区
///</summary>
public void ClearSendBuf()
{
if (hComm != INVALID_HANDLE_VALUE)
{
PurgeComm(hComm, PURGE_TXABORT | PURGE_TXCLEAR);
}
}
public static string ToHexString(byte[] bytes) // 0xae00cf => "AE00CF "
{
string hexString = string.Empty;
if (bytes != null)
{
StringBuilder strB = new StringBuilder();

for (int i = 0; i < bytes.Length; i++)
{
strB.Append(" " + bytes[i].ToString("X2"));
}
hexString = strB.ToString();
}
return hexString;
}
#region IDisposable 成员
public void Dispose()
{

ClearSendBuf();
ClearReceiveBuf();
}
#endregion
}