WinAPI 操作串口
public class CommPort
{
/// <summary>
/// 端口名称(COM1,COM2...COM4...)
/// </summary>
public string Port = "COM1:";
/// <summary>
/// 波特率9600
/// </summary>
public int BaudRate = 9600;
/// <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>
public int ReadTimeout = 200;
/// <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 = "\\windows\\coredll.dll"; // "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;
#region "标志"
///// <summary>
///// 指定是否允许二进制模式
///// </summary>
//public int fBinary;
///// <summary>
///// 指定是否允许奇偶校验
///// </summary>
//public int fParity;
///// <summary>
///// 指定CTS是否用于检测发送控制，当为TRUE是CTS为OFF，发送将被挂起。
///// </summary>
//public int fOutxCtsFlow;
///// <summary>
///// 指定CTS是否用于检测发送控制
///// </summary>
//public int fOutxDsrFlow;
///// <summary>
///// DTR_CONTROL_DISABLE值将DTR置为OFF, DTR_CONTROL_ENABLE值将DTR置为ON, DTR_CONTROL_HANDSHAKE允许DTR"握手"
///// </summary>
//public int fDtrControl;
///// <summary>
///// 当该值为TRUE时DSR为OFF时接收的字节被忽略
///// </summary>
//public int fDsrSensitivity;
///// <summary>
///// 指定当接收缓冲区已满,并且驱动程序已经发送出XoffChar字符时发送是否停止。
///// TRUE时，在接收缓冲区接收到缓冲区已满的字节XoffLim且驱动程序已经发送出
///// XoffChar字符中止接收字节之后，发送继续进行。 FALSE时，在接收缓冲区接
///// 收到代表缓冲区已空的字节XonChar且驱动程序已经发送出恢复发送的XonChar之
///// 后，发送继续进行。XOFF continues Tx
///// </summary>
//public int fTXContinueOnXoff;
///// <summary>
///// TRUE时，接收到XoffChar之后便停止发送接收到XonChar之后将重新开始 XON/XOFF
///// out flow control
///// </summary>
//public int fOutX;
///// <summary>
///// TRUE时，接收缓冲区接收到代表缓冲区满的XoffLim之后，XoffChar发送出去接收
///// 缓冲区接收到代表缓冲区空的XonLim之后，XonChar发送出去 XON/XOFF in flow control
///// </summary>
//public int fInX;
///// <summary>
///// 该值为TRUE且fParity为TRUE时，用ErrorChar 成员指定的字符代替奇偶校验错误
///// 的接收字符 enable error replacement
///// </summary>
//public int fErrorChar;
///// <summary>
///// eTRUE时，接收时去掉空（0值）字节 enable null stripping
///// </summary>
//public int fNull;
///// <summary>
///// RTS flow control RTS_CONTROL_DISABLE时,RTS置为OFF RTS_CONTROL_ENABLE时, RTS置为ON
///// RTS_CONTROL_HANDSHAKE时,当接收缓冲区小于半满时RTS为ON当接收缓冲区超过四分之
///// 三满时RTS为OFF RTS_CONTROL_TOGGLE时,当接收缓冲区仍有剩余字节时RTS为ON ,否则
///// 缺省为OFF
///// </summary>
//public int fRtsControl;
///// <summary>
///// TRUE时,有错误发生时中止读和写操作 abort on error
///// </summary>
//public int fAbortOnError;
///// <summary>
///// 未使用
///// </summary>
//public int fDummy2;
#endregion
/// <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()
{
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()
{
if (hComm != INVALID_HANDLE_VALUE)
{
CloseHandle(hComm);
}
}
/// <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)
{
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;
}
}
/// <summary>
/// 向串口写数据
/// </summary>
/// <param name="WriteBytes">数据数组</param>
public int Write(byte[] WriteBytes, int intSize)
{
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;
}
}
/// <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);
}
}
/// <summary>
/// 发送命令
/// </summary>
/// <param name="SendData"></param>
/// <param name="ReceiveData"></param>
/// <param name="Overtime"></param>
/// <returns></returns>
public int SendCommand(byte[] SendData, ref byte[] ReceiveData, int Overtime)
{
if (hComm != INVALID_HANDLE_VALUE)
{
COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
// 设置通信超时时间
GetCommTimeouts(hComm, ref ctoCommPort);
ctoCommPort.ReadTotalTimeoutConstant = Overtime;
ctoCommPort.ReadTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutConstant = 200; //叶帆 2007年11月21日
SetCommTimeouts(hComm, ref ctoCommPort);
ClearSendBuf();
ClearReceiveBuf();
Write(SendData, SendData.Length);
return Read(ref ReceiveData, ReceiveData.Length);
}
return -1;
}
}
