近日一个项目需要用在PDA上读取GPS卫星信号,在网上搜了一圈,整理出一个GPS的类,大家可以直接加入项目
使用。可以获得当前的经纬度、海拔、速度、连接卫星数等信息

Code
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using System;
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using System.Collections.Generic;
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using System.Text;
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using System.Runtime.InteropServices;
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namespace AnhlYiling
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{
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public class GPS
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{
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public string PortNum;
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public int BaudRate;
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public byte ByteSize;
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public byte Parity; // 0-4=no,odd,even,mark,space
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public byte StopBits; // 0,1,2 = 1, 1.5, 2
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public int ReadTimeout;
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//comm port win32 file handle
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private int hComm = -1;
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public bool Opened = false;
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//win32 api constants
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private const uint GENERIC_READ = 0x80000000;
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private const uint GENERIC_WRITE = 0x40000000;
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private const int OPEN_EXISTING = 3;
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private const int INVALID_HANDLE_VALUE = -1;
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[StructLayout(LayoutKind.Sequential)]
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public struct DCB
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{
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//taken from c struct in platform sdk
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public int DCBlength; // sizeof(DCB)
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public int BaudRate; // 指定当前波特率 current baud rate
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// these are the c struct bit fields, bit twiddle flag to set
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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
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public int fParity; // 指定是否允许奇偶校验 enable parity checking
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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
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public int fOutxDsrFlow; // 指定CTS是否用于检测发送控制 DSR output flow control
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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
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public int fDsrSensitivity; // 当该值为TRUE时DSR为OFF时接收的字节被忽略 DSR sensitivity
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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
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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
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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
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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
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public int fNull; // eTRUE时,接收时去掉空(0值)字节 enable null stripping
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public int fRtsControl; // RTS flow control
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/**//*RTS_CONTROL_DISABLE时,RTS置为OFF
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RTS_CONTROL_ENABLE时, RTS置为ON
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RTS_CONTROL_HANDSHAKE时,
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当接收缓冲区小于半满时RTS为ON
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当接收缓冲区超过四分之三满时RTS为OFF
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RTS_CONTROL_TOGGLE时,
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当接收缓冲区仍有剩余字节时RTS为ON ,否则缺省为OFF*/
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public int fAbortOnError; // TRUE时,有错误发生时中止读和写操作 abort on error
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public int fDummy2; // 未使用 reserved
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public uint flags;
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public ushort wReserved; // 未使用,必须为0 not currently used
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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
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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
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public byte ByteSize; // 指定端口当前使用的数据位 number of bits/byte, 4-8
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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
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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
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public char XonChar; // 指定用于发送和接收字符XON的值 Tx and Rx XON character
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public char XoffChar; // 指定用于发送和接收字符XOFF值 Tx and Rx XOFF character
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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
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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
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public char EvtChar; // 当接收到此字符时,会产生一个事件 received event character
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public ushort wReserved1; // 未使用 reserved; do not use
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}
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[StructLayout(LayoutKind.Sequential)]
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private struct COMMTIMEOUTS
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{
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public int ReadIntervalTimeout;
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public int ReadTotalTimeoutMultiplier;
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public int ReadTotalTimeoutConstant;
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public int WriteTotalTimeoutMultiplier;
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public int WriteTotalTimeoutConstant;
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}
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[StructLayout(LayoutKind.Sequential)]
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private struct OVERLAPPED
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{
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public int Internal;
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public int InternalHigh;
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public int Offset;
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public int OffsetHigh;
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public int hEvent;
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}
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[DllImport("coredll.dll")]
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private static extern int CreateFile(
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string lpFileName, // 要打开的串口名称
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uint dwDesiredAccess, // 指定串口的访问方式,一般设置为可读可写方式
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int dwShareMode, // 指定串口的共享模式,串口不能共享,所以设置为0
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int lpSecurityAttributes, // 设置串口的安全属性,WIN9X下不支持,应设为NULL
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int dwCreationDisposition, // 对于串口通信,创建方式只能为OPEN_EXISTING
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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
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int hTemplateFile // 对于串口通信必须设置为NULL
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);
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[DllImport("coredll.dll")]
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private static extern bool GetCommState(
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int hFile, //通信设备句柄
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ref DCB lpDCB // 设备控制块DCB
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);
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[DllImport("coredll.dll")]
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private static extern bool BuildCommDCB(
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string lpDef, // 设备控制字符串
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ref DCB lpDCB // 设备控制块
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);
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[DllImport("coredll.dll")]
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private static extern bool SetCommState(
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int hFile, // 通信设备句柄
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ref DCB lpDCB // 设备控制块
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);
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[DllImport("coredll.dll")]
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private static extern bool GetCommTimeouts(
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int hFile, // 通信设备句柄 handle to comm device
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ref COMMTIMEOUTS lpCommTimeouts // 超时时间 time-out values
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);
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[DllImport("coredll.dll")]
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private static extern bool SetCommTimeouts(
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int hFile, // 通信设备句柄 handle to comm device
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ref COMMTIMEOUTS lpCommTimeouts // 超时时间 time-out values
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);
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[DllImport("coredll.dll")]
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private static extern bool ReadFile(
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int hFile, // 通信设备句柄 handle to file
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byte[] lpBuffer, // 数据缓冲区 data buffer
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int nNumberOfBytesToRead, // 多少字节等待读取 number of bytes to read
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ref int lpNumberOfBytesRead, // 读取多少字节 number of bytes read
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ref OVERLAPPED lpOverlapped // 溢出缓冲区 overlapped buffer
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);
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[DllImport("coredll.dll")]
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private static extern bool WriteFile(
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int hFile, // 通信设备句柄 handle to file
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byte[] lpBuffer, // 数据缓冲区 data buffer
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int nNumberOfBytesToWrite, // 多少字节等待写入 number of bytes to write
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ref int lpNumberOfBytesWritten, // 已经写入多少字节 number of bytes written
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ref OVERLAPPED lpOverlapped // 溢出缓冲区 overlapped buffer
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);
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[DllImport("coredll.dll")]
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private static extern bool CloseHandle(
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int hObject // handle to object
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);
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[DllImport("coredll.dll")]
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private static extern uint GetLastError();
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public void Open()
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{
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DCB dcbCommPort = new DCB();
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COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
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// 打开串口 OPEN THE COMM PORT.
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hComm = CreateFile(PortNum ,GENERIC_READ | GENERIC_WRITE,0, 0,OPEN_EXISTING,0,0);
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// 如果串口没有打开,就打开 IF THE PORT CANNOT BE OPENED, BAIL OUT.
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if(hComm == INVALID_HANDLE_VALUE)
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{
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throw(new ApplicationException("非法操作,不能打开串口!"));
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}
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// 设置通信超时时间 SET THE COMM TIMEOUTS.
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GetCommTimeouts(hComm,ref ctoCommPort);
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ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
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ctoCommPort.ReadTotalTimeoutMultiplier = 0;
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ctoCommPort.WriteTotalTimeoutMultiplier = 0;
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ctoCommPort.WriteTotalTimeoutConstant = 0;
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SetCommTimeouts(hComm,ref ctoCommPort);
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// 设置串口 SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.
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GetCommState(hComm, ref dcbCommPort);
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dcbCommPort.BaudRate=BaudRate;
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dcbCommPort.flags=0;
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//dcb.fBinary=1;
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dcbCommPort.flags|=1;
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if (Parity>0)
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{
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//dcb.fParity=1
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dcbCommPort.flags|=2;
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}
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dcbCommPort.Parity=Parity;
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dcbCommPort.ByteSize=ByteSize;
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dcbCommPort.StopBits=StopBits;
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if (!SetCommState(hComm, ref dcbCommPort))
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{
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//uint ErrorNum=GetLastError();
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throw(new ApplicationException("非法操作,不能打开串口!"));
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}
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//unremark to see if setting took correctly
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//DCB dcbCommPort2 = new DCB();
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//GetCommState(hComm, ref dcbCommPort2);
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Opened = true;
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}
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public void Close()
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{
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if (hComm!=INVALID_HANDLE_VALUE)
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{
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CloseHandle(hComm);
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}
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}
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public byte[] Read(int NumBytes)
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{
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byte[] BufBytes;
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byte[] OutBytes;
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BufBytes = new byte[NumBytes];
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if (hComm!=INVALID_HANDLE_VALUE)
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{
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OVERLAPPED ovlCommPort = new OVERLAPPED();
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int BytesRead=0;
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ReadFile(hComm,BufBytes,NumBytes,ref BytesRead,ref ovlCommPort);
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try
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{
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OutBytes = new byte[BytesRead];
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Array.Copy(BufBytes,0,OutBytes,0,BytesRead);
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}
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catch
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{
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return BufBytes;
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}
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}
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else
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{
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throw(new ApplicationException("串口未打开!"));
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}
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return OutBytes;
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// return BufBytes;
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}
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public void Write(byte[] WriteBytes)
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{
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if (hComm!=INVALID_HANDLE_VALUE)
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{
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OVERLAPPED ovlCommPort = new OVERLAPPED();
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int BytesWritten = 0;
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WriteFile(hComm,WriteBytes,WriteBytes.Length,ref BytesWritten,ref ovlCommPort);
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}
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else
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{
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throw(new ApplicationException("串口未打开!"));
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}
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}
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public string GetGPS(string hander,string strGPS,string strFind)
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{
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/**////从GPS中读取的数据中,找出想要的数据
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///GPSstring原始字符串,
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///strFind要查找的内容,X:经度,Y:纬度,T:时间,V:速度,N 当前可用卫星数量,H 当前海拔
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///返回查找到指定位置的字符串
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if (hander.Equals("$GPRMC"))
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{
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string handerStr = hander;//GPS串头
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int findHander = strGPS.IndexOf(handerStr);//看是否含有GPS串头
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if (findHander < 0)
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{
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return "-1";
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}
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else
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{
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strGPS = strGPS.Substring(findHander, strGPS.Length - findHander);
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string[] ArryTmp = strGPS.Split(",".ToCharArray());
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try
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{
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if (ArryTmp[2] == "V")
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{
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return "GPS没有信号";//没有信号
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}
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else
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{
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switch (strFind)
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{
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case "X":
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return DM2DD(ArryTmp[5]);
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case "Y":
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return DM2DD(ArryTmp[3]);
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case "T":
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return T2Time(ArryTmp[9], ArryTmp[1]);
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case "V":
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return Convert.ToString(Convert.ToDouble(ArryTmp[7]) * 1.852);
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case "K":
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return ArryTmp[7];
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default:
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return "V";
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}
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}
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}
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catch
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{
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return "V";
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}
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}
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}
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else if (hander.Equals("$GPGGA"))
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{
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string handerStr = hander;//GPS串头
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int findHander = strGPS.IndexOf(handerStr);//看是否含有GPS串头
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if (findHander < 0)
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{
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return "-1";
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}
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else
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{
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strGPS = strGPS.Substring(findHander, strGPS.Length - findHander);
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string[] ArryTmp = strGPS.Split(",".ToCharArray());
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switch (strFind)
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{
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case "N":
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return ArryTmp[7];
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case "H":
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return ArryTmp[9];
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default:
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return "无法解析的命令.";
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}
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}
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}
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return null;
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}
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public string T2Time(string strDate,string strTime)
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{
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string dT="20"+strDate.Substring(4,2)+"-"+strDate.Substring(2,2)+"-"+strDate.Substring(0,2);
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string TT=Convert.ToString(Convert.ToInt32(strTime.Substring(0,2)))+":"+strTime.Substring(2,2)+":"+strTime.Substring(4,2);
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DateTime T=Convert.ToDateTime(dT+" "+TT);
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T=T.AddHours(8);
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return T.ToString();
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}
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public string DM2DD(string DegreeMinutes)
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{
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//转换NMEA协议的“度分”格式为十进制“度度”格式
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string sDegree;
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string sMinute;
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string sReturn="";
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if(DegreeMinutes.IndexOf(".")==4)
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{
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//DegreeMinutes = Replace(DegreeMinutes, ".", "")
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//DM2DD = CDbl(Left(DegreeMinutes, 2)) + CDbl(Left(CStr(CDbl(Right(DegreeMinutes, Len(DegreeMinutes) - 2)) / 60), 8)) / 10000
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DegreeMinutes=DegreeMinutes.Replace(".","");
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double sDegree1=Convert.ToDouble(DegreeMinutes.Substring(0,2));
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double sDegree2=Convert.ToDouble(DegreeMinutes.Substring(2,DegreeMinutes.Length-2));
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string sTmp=Convert.ToString(sDegree2/60);
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sDegree2=Convert.ToDouble(sTmp.Substring(0,sTmp.Length));
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sDegree2=sDegree2/10000;
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sDegree=Convert.ToString(sDegree1+sDegree2);
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if(sDegree.Length>11)
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sDegree=sDegree.Substring(0,11);
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sReturn=sDegree;
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}
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else if(DegreeMinutes.IndexOf(".")==5)
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{
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//DegreeMinutes = Replace(DegreeMinutes, ".", "")
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//DM2DD = CDbl(Left(DegreeMinutes, 2)) + CDbl(Left(CStr(CDbl(Right(DegreeMinutes, Len(DegreeMinutes) - 2)) / 60), 8)) / 10000
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DegreeMinutes=DegreeMinutes.Replace(".","");
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double sMinute1=Convert.ToDouble(DegreeMinutes.Substring(0,3));
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double sMinute2=Convert.ToDouble(DegreeMinutes.Substring(3,DegreeMinutes.Length-3));
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string sTmp=Convert.ToString(sMinute2/60);
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sMinute2=Convert.ToDouble(sTmp.Substring(0,sTmp.Length));
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sMinute2=sMinute2/10000;
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sMinute=Convert.ToString(sMinute1+sMinute2);
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if(sMinute.Length>10)
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sMinute=sMinute.Substring(0,10);
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sReturn=sMinute;
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}
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return sReturn;
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}
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public bool ScanPort()
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{
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try
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{
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if (Opened)
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{
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Close();
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Open();
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}
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else
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{
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Open();//打开串口
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}
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byte[] bytRead=Read(512);
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Close();
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if(Encoding.ASCII.GetString(bytRead,0,bytRead.Length).IndexOf("$GP")>=0)
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return true;
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else
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return false;
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}
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catch
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{
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return false;
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}
406
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}
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}
409
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class HexCon
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{
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// 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
413
public static string ByteToString(byte[] InBytes)
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{
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string StringOut="";
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foreach (byte InByte in InBytes)
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{
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StringOut=StringOut + String.Format("{0:X2} ",InByte);
419
}
420
return StringOut;
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}
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public static byte[] StringToByte(string InString)
423
{
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string[] ByteStrings;
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ByteStrings = InString.Split(" ".ToCharArray());
426
byte[] ByteOut;
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ByteOut = new byte[ByteStrings.Length-1];
428
for (int i = 0;i==ByteStrings.Length-1;i++)
429
{
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ByteOut[i] = Convert.ToByte(("0x" + ByteStrings[i]));
431
}
432
return ByteOut;
433
}
434
435
}
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}
437
调用很简单:
1 GPS ss_port = new GPS();
2 ss_port.PortNum = "COM4:"; //串口号.后面一定要有':'
3 ss_port.BaudRate = 4800;
4 ss_port.ByteSize = 8;
5 ss_port.Parity = 0;
6 ss_port.StopBits = 1;
7 ss_port.ReadTimeout = 1000;
8
9 try
10 {
11 if (ss_port.Opened)
12 {
13 ss_port.Close();
14 ss_port.Open();
15 timer1.Enabled = true;
16 }
17 else
18 {
19 ss_port.Open();//打开串口
20 label1.Text = "已打开";
21 timer1.Enabled = true;
22 }
23
24 }
25 catch (Exception e1)
26 {
27 label1.Text = e1.Message;
28
29 }