serialport.cs

c#编写的带控件GPS接收程序

#region Using directives

using System;
using System.Windows.Forms;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Threading;

#endregion

namespace GpsSerialPortProgram
{
    public enum openPortResult
    {
        OpenFailed,
        None,
        FindGps
    }

    public delegate void CurrentDataEventHandler(object sender,NewDataEventArgs e);

    public class SerialPort
    {
        #region 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;

        #endregion

        #region User defined variables

        int hPortHandle = INVALID_HANDLE_VALUE;
        private bool opened = false;
        public event CurrentDataEventHandler UpdateDataEventHandler;

        #endregion

        #region serialport structure

        [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;
        }

        #endregion

        #region DllImport serial port operation from coredll.dll

        [DllImport("coredll.dll")]
        public static extern int CreateFile(string lpFileName,
                                            uint dwDesiredAccess,
                                            int dwShareMode,
                                            int lpSecurityAttributes,
                                            int dwCreationDisposition,
                                            int dwFlagsAndAttributes,
                                            int hTemplateFile);

        [DllImport("coredll.dll")]
        private static extern bool GetCommState(int hFile, ref DCB lpDCB);

        [DllImport("coredll.dll")]
        private static extern bool BuildCommDCB(string lpDef, ref DCB lpDCB);

        [DllImport("coredll.dll")]
        private static extern bool SetCommState(int hFile, ref DCB lpDCB);

        [DllImport("coredll.dll")]
        private static extern bool GetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts);

        [DllImport("coredll.dll")]
        private static extern bool SetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts);

        [DllImport("coredll.dll")]
        private static extern bool ReadFile(int hFile,
                                          Byte[] lpBuffer,
                                          int nNumberOfBytesToRead,
                                          ref int lpNumberOfBytesRead,
                                          ref OVERLAPPED lpOverlapped);

        [DllImport("coredll.dll")]
        private static extern bool WriteFile(int hFile,
                                          Byte[] lpBuffer,
                                          int nNumberOfBytesToWrite,
                                          ref int lpNumberOfBytesWritten,
                                          ref OVERLAPPED lpOverlapped);

        [DllImport("coredll.dll")]
        private static extern bool CloseHandle(int hObject);

        [DllImport("coredll.dll")]
        private static extern uint GetLastError();

        #endregion

        public void Open(string selectedPort, int baudRate)
        {
            DCB commDCB = new DCB();
            COMMTIMEOUTS commTimeouts = new COMMTIMEOUTS();

            hPortHandle = CreateFile(selectedPort, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

            if (hPortHandle == INVALID_HANDLE_VALUE)
            {
                //MessageBox.Show("打开串口失败！");
                opened = false;
            }
            else
            {
                //设置串口状态参数
                GetCommState(hPortHandle, ref commDCB);
                commDCB.BaudRate = baudRate;
                commDCB.Parity = 0;
                commDCB.StopBits = 1;
                commDCB.ByteSize = 8;
                SetCommState(hPortHandle, ref commDCB);

                //设置串口超时参数
                GetCommTimeouts(hPortHandle, ref commTimeouts);
                commTimeouts.ReadTotalTimeoutConstant = 1000;
                commTimeouts.ReadTotalTimeoutMultiplier = 0;
                commTimeouts.WriteTotalTimeoutMultiplier = 10;
                commTimeouts.WriteTotalTimeoutConstant = 1000;
                SetCommTimeouts(hPortHandle, ref commTimeouts);
                opened = true;
            }
        }

        public void Read(ref Byte[] buffer)
        {
            if (hPortHandle != INVALID_HANDLE_VALUE)
            {
                OVERLAPPED ovlCommPort = new OVERLAPPED();
                int BytesRead = 0;
                ReadFile(hPortHandle, buffer, buffer.Length, ref BytesRead, ref ovlCommPort);
            }
            else
            {
                throw new Exception("串口未打开！");
                //throw (new ApplicationException("串口未打开！"));