串口通信类JustinIO.CommPort及使用方法

 using System;

 using System.Runtime.InteropServices;

 using System.Text;

 namespace JustinIO
 {

     public class CommPort
     {

         public string PortName;

         public int BaudRate;

         public byte DataBits;

         public byte Parity; // 0-4=no,odd,even,mark,space

         public byte StopBits; // 0,1,2 = 1, 1.5, 2

         public int ReadTimeout;

         //comm port win32 file handle

         private int hComm = -1;

         public bool Opened = false;

         public bool IsOpen = false;

         //win32 api constants

         private const uint GENERIC_READ = 0x80000000;

         private const uint GENERIC_WRITE = 0x40000000;

         private const int OPEN_EXISTING = 3;

         private const int INVALID_HANDLE_VALUE = -1;

         [StructLayout(LayoutKind.Sequential)]

         public struct DCB
         {

             //taken from c struct in platform sdk

             public int DCBlength; // sizeof(DCB)

             public int BaudRate; // 指定当前波特率 current baud rate

             // these are the c struct bit fields, bit twiddle flag to set

             public int fBinary; // 指定是否允许二进制模式,在windows95中必须主TRUE binary mode, no EOF check

             public int fParity; // 指定是否允许奇偶校验 enable parity checking

             public int fOutxCtsFlow; // 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。 CTS output flow control

             public int fOutxDsrFlow; // 指定CTS是否用于检测发送控制 DSR output flow control

             public int fDtrControl; // 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" DTR flow control type

             public int fDsrSensitivity; // 当该值为TRUE时DSR为OFF时接收的字节被忽略 DSR sensitivity

             public int fTXContinueOnXoff; // 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

             public int fOutX; // 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

             public int fInX; // 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

             public int fErrorChar; // 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

             public int fNull; // eTRUE时，接收时去掉空（0值）字节 enable null stripping

             public int fRtsControl; // 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*/

             public int fAbortOnError; // TRUE时,有错误发生时中止读和写操作 abort on error

             public int fDummy2; // 未使用 reserved

             public uint flags;

             public ushort wReserved; // 未使用,必须为0 not currently used

             public ushort XonLim; // 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 transmit XON threshold

             public ushort XoffLim; // 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 transmit XOFF threshold

             public byte ByteSize; // 指定端口当前使用的数据位 number of bits/byte, 4-8

             public byte Parity; // 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

             public byte StopBits; // 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

             public char XonChar; // 指定用于发送和接收字符XON的值 Tx and Rx XON character

             public char XoffChar; // 指定用于发送和接收字符XOFF值 Tx and Rx XOFF character

             public char ErrorChar; // 本字符用来代替接收到的奇偶校验发生错误时的值 error replacement character

             public char EofChar; // 当没有使用二进制模式时,本字符可用来指示数据的结束 end of input character

             public char EvtChar; // 当接收到此字符时,会产生一个事件 received event character

             public ushort wReserved1; // 未使用 reserved; do not use

         }

         [StructLayout(LayoutKind.Sequential)]

         private struct COMMTIMEOUTS
         {

             public int ReadIntervalTimeout;

             public int ReadTotalTimeoutMultiplier;

             public int ReadTotalTimeoutConstant;

             public int WriteTotalTimeoutMultiplier;

             public int WriteTotalTimeoutConstant;

         }

         [StructLayout(LayoutKind.Sequential)]

         private struct OVERLAPPED
         {

             public int Internal;

             public int InternalHigh;

             public int Offset;

             public int OffsetHigh;

             public int hEvent;

         }

         [DllImport("kernel32.dll")]

         private static extern int CreateFile(

         string lpFileName, // 要打开的串口名称

         uint dwDesiredAccess, // 指定串口的访问方式，一般设置为可读可写方式

         int dwShareMode, // 指定串口的共享模式，串口不能共享，所以设置为0

         int lpSecurityAttributes, // 设置串口的安全属性，WIN9X下不支持，应设为NULL

         int dwCreationDisposition, // 对于串口通信，创建方式只能为OPEN_EXISTING

         int 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

         int hTemplateFile // 对于串口通信必须设置为NULL

         );

         [DllImport("kernel32.dll")]

         private static extern bool GetCommState(

         int hFile, //通信设备句柄

         ref DCB lpDCB // 设备控制块DCB

         );

         [DllImport("kernel32.dll")]

         private static extern bool BuildCommDCB(

         string lpDef, // 设备控制字符串

         ref DCB lpDCB // 设备控制块

         );

         [DllImport("kernel32.dll")]

         private static extern bool SetCommState(

         int hFile, // 通信设备句柄

         ref DCB lpDCB // 设备控制块

         );

         [DllImport("kernel32.dll")]

         private static extern bool GetCommTimeouts(

         int hFile, // 通信设备句柄 handle to comm device

         ref COMMTIMEOUTS lpCommTimeouts // 超时时间 time-out values

         );

         [DllImport("kernel32.dll")]

         private static extern bool SetCommTimeouts(

         int hFile, // 通信设备句柄 handle to comm device

         ref COMMTIMEOUTS lpCommTimeouts // 超时时间 time-out values

         );

         [DllImport("kernel32.dll")]

         private static extern bool ReadFile(

         int hFile, // 通信设备句柄 handle to file

         byte[] lpBuffer, // 数据缓冲区 data buffer

         int nNumberOfBytesToRead, // 多少字节等待读取 number of bytes to read

         ref int lpNumberOfBytesRead, // 读取多少字节 number of bytes read

         ref OVERLAPPED lpOverlapped // 溢出缓冲区 overlapped buffer

         );

         [DllImport("kernel32.dll")]

         private static extern bool WriteFile(

         int hFile, // 通信设备句柄 handle to file

         byte[] lpBuffer, // 数据缓冲区 data buffer

         int nNumberOfBytesToWrite, // 多少字节等待写入 number of bytes to write

         ref int lpNumberOfBytesWritten, // 已经写入多少字节 number of bytes written

         ref OVERLAPPED lpOverlapped // 溢出缓冲区 overlapped buffer

         );

         [DllImport("kernel32.dll")]

         private static extern bool CloseHandle(

         int hObject // handle to object

         );

         [DllImport("kernel32.dll")]

         private static extern uint GetLastError();

         public void Open()
         {

             DCB dcbCommPort = new DCB();

             COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();

             // 打开串口 OPEN THE COMM PORT.

             string num = PortName.Replace("COM", "");

             if (int.Parse(num) >= 10)

                 hComm = CreateFile("//./"" + PortName, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

             else

                 hComm = CreateFile(PortName, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

             // 如果串口没有打开，就打开 IF THE PORT CANNOT BE OPENED, BAIL OUT.

             if (hComm == INVALID_HANDLE_VALUE)
             {

                 throw (new Exception("非法操作，不能打开串口！"));

             }

             // 设置通信超时时间 SET THE COMM TIMEOUTS.

             GetCommTimeouts(hComm, ref ctoCommPort);

             ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;

             ctoCommPort.ReadTotalTimeoutMultiplier = 0;

             ctoCommPort.WriteTotalTimeoutMultiplier = 0;

             ctoCommPort.WriteTotalTimeoutConstant = 0;

             SetCommTimeouts(hComm, ref ctoCommPort);

             // 设置串口 SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.

             GetCommState(hComm, ref dcbCommPort);

             dcbCommPort.BaudRate = BaudRate;

             dcbCommPort.flags = 0;

             //dcb.fBinary=1;

             dcbCommPort.flags |= 1;

             if (Parity > 0)
             {

                 //dcb.fParity=1

                 dcbCommPort.flags |= 2;

             }

             dcbCommPort.Parity = Parity;

             dcbCommPort.ByteSize = DataBits;

             dcbCommPort.StopBits = StopBits;

             if (!SetCommState(hComm, ref dcbCommPort))
             {

                 //uint ErrorNum=GetLastError();

                 throw (new ApplicationException("非法操作，不能打开串口！"));

             }

             //unremark to see if setting took correctly

             //DCB dcbCommPort2 = new DCB();

             //GetCommState(hComm, ref dcbCommPort2);

             Opened = true;

             IsOpen = true;

         }

         public void Close()
         {

             if (hComm != INVALID_HANDLE_VALUE)
             {

                 CloseHandle(hComm);

             }

         }

         public byte[] Read(int NumBytes)
         {

             byte[] BufBytes;

             byte[] OutBytes;

             BufBytes = new byte[NumBytes];

             if (hComm != INVALID_HANDLE_VALUE)
             {

                 OVERLAPPED ovlCommPort = new OVERLAPPED();

                 int BytesRead = 0;

                 ReadFile(hComm, BufBytes, NumBytes, ref BytesRead, ref ovlCommPort);

                 OutBytes = new byte[BytesRead];

                 Array.Copy(BufBytes, OutBytes, BytesRead);

             }

             else
             {

                 throw (new ApplicationException("串口未打开！"));

             }

             return OutBytes;

         }

         public string ReadExisting()
         {

             return Encoding.ASCII.GetString(Read(128));

         }

         public void Write(byte[] WriteBytes)
         {

             if (hComm != INVALID_HANDLE_VALUE)
             {

                 OVERLAPPED ovlCommPort = new OVERLAPPED();

                 int BytesWritten = 0;

                 WriteFile(hComm, WriteBytes, WriteBytes.Length, ref BytesWritten, ref ovlCommPort);

             }

             else
             {

                 throw (new ApplicationException("串口未打开！"));

             }

         }

         public void Write(string WriteString, Encoding CoderType)
         {

             Write(CoderType.GetBytes(WriteString));

         }

         public void Write(string WriteString)
         {

             Write(Encoding.ASCII.GetBytes(WriteString));

         }

     }

 }

介绍JustinIO的使用方法： 

打开串口： 

函数原型：public void Open() 

说明：打开事先设置好的端口 

示例： 

using JustinIO; 

static JustinIO.CommPort ss_port = new JustinIO.CommPort(); 
ss_port.PortNum = COM1; //端口号 
ss_port.BaudRate = 19200; //串口通信波特率 
ss_port.ByteSize = 8; //数据位 
ss_port.Parity = 0; //奇偶校验 
ss_port.StopBits = 1;//停止位 
ss_port.ReadTimeout = 1000; //读超时 
try 
{ 
if (ss_port.Opened) 
{ 
ss_port.Close(); 
ss_port.Open(); //打开串口 
} 
else 
{ 
ss_port.Open();//打开串口 
} 
return true; 
} 
catch(Exception e) 
{ 
MessageBox.Show("错误：" + e.Message); 
return false; 
} 

写串口： 

函数原型：public void Write(byte[] WriteBytes) 

WriteBytes 就是你的写入的字节，注意，字符串要转换成字节数组才能进行通信 

示例： 

ss_port.Write(Encoding.ASCII.GetBytes("AT+CGMI/r")); //获取手机品牌 

读串口： 

函数原型：public byte[] Read(int NumBytes) 

NumBytes 读入缓存数，注意读取来的是字节数组，要实际应用中要进行字符转换 

示例： 

string response = Encoding.ASCII.GetString(ss_port.Read(128)); //读取128个字节缓存 

关闭串口： 

函数原型：ss_port.Close() 

示例： 

ss_port.Close(); 

这个好像有点问题啊，网上查了下，Close方法里面需要加个Opened=false；但是如果打开串口，连续关闭2次串口就报错了，不知道怎么解决。