GPS和PDA 的串口通信程序

最近搞了PDA 和GPS相结合的一个项目,在写串口程序的时候遇到了一点问题,困饶了好几天都没有解决.最后是因为测试的方法不对引起的.我测试的时候是现在一台机器上面写一个字符串，然后读取他，结果啥都没读到，后来连了串口线进行测试就对了，就是用串口线把计算机和pda连接起来，然后在pda上部署一个简单的测试程序，在计算机上通过串口调试助手不断的发数据，然后pda点接收按纽，哈哈，就有数据了哦！

川口操作的过程实现打开串口，然后读取，然后关闭。

PDA要接收GPS 发来的信息.我用的开发工具是c#.net,compact framework 2003,PDA 模拟器

.net2003并没有提供相应的操作串口的类,所以要自己调用windows的api,具体的代码如下: 
using System;
using System.Collections;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.IO;

namespace Port
{
 public class Port
 {
  public byte[] OutBytes;
  public byte[] mbytTxBuffer;
  public int strNum;
  public string PortNum;
  public int BaudRate;
  public byte ByteSize;
  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;
  //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("coredll.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("coredll.dll")]
  private static extern int GetCommState(
   int hFile, //通信设备句柄
   ref DCB lpDCB // 设备控制块DCB
   );
  [DllImport("coredll.dll")]
  private static extern bool BuildCommDCB(
   string lpDef, // 设备控制字符串
   ref DCB lpDCB // 设备控制块
   );
  [DllImport("coredll.dll")]
  private static extern bool SetCommState(
   int hFile, // 通信设备句柄
   ref DCB lpDCB // 设备控制块
   );
  [DllImport("coredll.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("coredll.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("coredll.dll")]
  private static extern int 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("coredll.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("coredll.dll")]
  private static extern bool CloseHandle(
   int hObject // handle to object
   );
  [DllImport("coredll.dll")]
  private static extern uint GetLastError();
  [DllImport("coredll.dll")]
  private static extern int PurgeComm(int hFile,int dwFlags);

 

 

  //打开串口的程序；
  public void Open()
  {
   
   DCB dcbCommPort = new DCB();
   COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
   hComm = CreateFile(PortNum, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
   MessageBox.Show("hComm is :"+hComm);
   // 如果串口没有打开
   if (hComm == INVALID_HANDLE_VALUE)
   {
    throw (new ApplicationException("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;
   dcbCommPort.flags |= 1;
   if (Parity > 0)
   {
    dcbCommPort.flags |= 2;
   }
   dcbCommPort.Parity = Parity;
   dcbCommPort.ByteSize = ByteSize;
   dcbCommPort.StopBits = StopBits;
   if (!SetCommState(hComm, ref dcbCommPort))
   {
    throw (new ApplicationException("非法操作，不能打开串口！"));
   }
   Opened = true;
  }
  public void Close()
  {
   if (hComm != INVALID_HANDLE_VALUE)
   {
    CloseHandle(hComm);
   }
  }

 //读数据
   public byte[] Read(int NumBytes)
   {  
    byte[] 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,0,OutBytes,0,BytesRead);
     strNum = BytesRead;
    }
    else
    {
     throw (new ApplicationException("串口未打开！"));
    }
    MessageBox.Show("OutBytes.length  is :"+OutBytes.Length);
    return OutBytes;

    
   }
  
 
    //来源自.net compact framework 技术内幕第11章串行通信第347页

　//用的就是这个方法来读的

  public string Input(int BytesToRead)
  {
   string result="";
   int intResult;
   ASCIIEncoding objEncoder=new ASCIIEncoding();
   int lpNumberOfBytesRead=0;
   OVERLAPPED lpOverlapped;
   if(BytesToRead==0)
    BytesToRead=512;
   if(hComm!=-1)
   {
    OutBytes=new byte[BytesToRead];
    lpOverlapped=new OVERLAPPED();
    intResult=ReadFile(hComm, OutBytes, BytesToRead, ref lpNumberOfBytesRead, ref lpOverlapped);
    if(intResult==0)
    {
     hComm=-1;
     throw (new ApplicationException("串口未打开！"));

    }
    else
    {
     result=objEncoder.GetString(OutBytes,0,BytesToRead);
     MessageBox.Show("result  is :"+result);

    }

   }
   return result;
  
  }

  //这个方法是把数据写到串口上的，来源自.net compact framework 技术内幕第11章串行通信第347页

//没有用到这个方法暂时

  public void Output(string Value)
  {
   int lpNumberOfBytesWritten=0;
   OVERLAPPED lpOverlapped=new OVERLAPPED();
   ASCIIEncoding objEncoder=new ASCIIEncoding();
   MessageBox.Show("hComm is :"+hComm);
   if(hComm!=-1)
   {
    mbytTxBuffer=new byte[Value.Length];
    mbytTxBuffer=objEncoder.GetBytes(Value);
    bool m_boo=false;   
    m_boo=WriteFile(hComm,mbytTxBuffer,mbytTxBuffer.Length,ref lpNumberOfBytesWritten,ref lpOverlapped);
    if(m_boo==true)
    {
     MessageBox.Show("写成功了");
    }
    else
    {
     MessageBox.Show("没有成功！!");
    }
   }
  }

  // 这个方法也是写数据到串口的
  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 class HexCon
 {
  // 把十六进制字符串转换成字节型和把字节型转换成十六进制字符串 converter hex string to byte and byte to hex string
  public static string ByteToString(byte[] InBytes)
  {
   string StringOut = "";
   foreach (byte InByte in InBytes)
   {
    StringOut = StringOut + String.Format("{0:X2} ", InByte);
   }
   return StringOut;
  }

  public static byte[] StringToByte(string InString)
  {
   string[] ByteStrings;
   ByteStrings = InString.Split(" ".ToCharArray());
   byte[] ByteOut;
   ByteOut = new byte[ByteStrings.Length];
   for (int i = 0; i <= ByteStrings.Length - 1; i++)
   {
    ByteOut[i] = Convert.ToByte(ByteStrings[i], 16);
   }
   return ByteOut;
  }
 }
   
}