最近搞了PDA 和GPS相結(jié)合的一個(gè)項(xiàng)目，在寫串口程序的時(shí)候遇到了一點(diǎn)問(wèn)題，困饒了好幾天都沒(méi)有解決。最后是因?yàn)闇y(cè)試的方法不對(duì)引起的。我測(cè)試的時(shí)候是現(xiàn)在一臺(tái)機(jī)器上面寫一個(gè)字符串，然后讀取，結(jié)果啥都沒(méi)讀到，后來(lái)連了串口線進(jìn)行測(cè)試就對(duì)了，就是用串口線把計(jì)算機(jī)和pda連接起來(lái)，然后在pda上部署一個(gè)簡(jiǎn)單的測(cè)試程序，在計(jì)算機(jī)上通過(guò)串口調(diào)試助手不斷的發(fā)數(shù)據(jù)，然后pda點(diǎn)接收按鈕，哈哈，就有數(shù)據(jù)了哦！
串口操作的過(guò)程實(shí)現(xiàn)打開(kāi)串口，然后讀取，然后關(guān)閉。
PDA要接收GPS發(fā)來(lái)的信息。我用的開(kāi)發(fā)工具是c#.net、compact framework 2003、PDA 模擬器
.net2003并沒(méi)有提供相應(yīng)的操作串口的類，所以要自己調(diào)用windows的api，具體的代碼如下:
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; // 指定當(dāng)前波特率 current baud rate
// these are the c struct bit fields, bit twiddle flag to set
public int fBinary; // 指定是否允許二進(jìn)制模式,在windows95中必須主TRUE binary mode, no EOF check
public int fParity; // 指定是否允許奇偶校驗(yàn) enable parity checking
public int fOutxCtsFlow; // 指定CTS是否用于檢測(cè)發(fā)送控制，當(dāng)為TRUE是CTS為OFF，發(fā)送將被掛起。 CTS output flow control
public int fOutxDsrFlow; // 指定CTS是否用于檢測(cè)發(fā)送控制 DSR output flow control
public int fDtrControl; // DTR_CONTROL_DISABLE值將DTR置為OFF, DTR_CONTROL_ENABLE值將DTR置為ON, DTR_CONTROL_HANDSHAKE允許DTR"握手" DTR flow control type
public int fDsrSensitivity; // 當(dāng)該值為TRUE時(shí)DSR為OFF時(shí)接收的字節(jié)被忽略 DSR sensitivity
public int fTXContinueOnXoff; // 指定當(dāng)接收緩沖區(qū)已滿,并且驅(qū)動(dòng)程序已經(jīng)發(fā)送出XoffChar字符時(shí)發(fā)送是否停止。TRUE時(shí)，在接收緩沖區(qū)接收到緩沖區(qū)已滿的字節(jié)XoffLim且驅(qū)動(dòng)程序已經(jīng)發(fā)送出XoffChar字符中止接收字節(jié)之后，發(fā)送繼續(xù)進(jìn)行�！ALSE時(shí)，在接收緩沖區(qū)接收到代表緩沖區(qū)已空的字節(jié)XonChar且驅(qū)動(dòng)程序已經(jīng)發(fā)送出恢復(fù)發(fā)送的XonChar之后，發(fā)送繼續(xù)進(jìn)行。XOFF continues Tx
public int fOutX; // TRUE時(shí)，接收到XoffChar之后便停止發(fā)送接收到XonChar之后將重新開(kāi)始 XON/XOFF out flow control
public int fInX; // TRUE時(shí)，接收緩沖區(qū)接收到代表緩沖區(qū)滿的XoffLim之后，XoffChar發(fā)送出去接收緩沖區(qū)接收到代表緩沖區(qū)空的XonLim之后，XonChar發(fā)送出去 XON/XOFF in flow control
public int fErrorChar; // 該值為TRUE且fParity為TRUE時(shí)，用ErrorChar 成員指定的字符代替奇偶校驗(yàn)錯(cuò)誤的接收字符 enable error replacement
public int fNull; // eTRUE時(shí)，接收時(shí)去掉空（0值）字節(jié) enable null stripping
public int fRtsControl; // RTS flow control
/*RTS_CONTROL_DISABLE時(shí),RTS置為OFF
RTS_CONTROL_ENABLE時(shí), RTS置為ON
RTS_CONTROL_HANDSHAKE時(shí),
當(dāng)接收緩沖區(qū)小于半滿時(shí)RTS為ON
當(dāng)接收緩沖區(qū)超過(guò)四分之三滿時(shí)RTS為OFF
RTS_CONTROL_TOGGLE時(shí),
當(dāng)接收緩沖區(qū)仍有剩余字節(jié)時(shí)RTS為ON ,否則缺省為OFF*/
public int fAbortOnError; // TRUE時(shí),有錯(cuò)誤發(fā)生時(shí)中止讀和寫操作 abort on error
public int fDummy2; // 未使用 reserved
public uint flags;
public ushort wReserved; // 未使用,必須為0 not currently used
public ushort XonLim; // 指定在XON字符發(fā)送這前接收緩沖區(qū)中可允許的最小字節(jié)數(shù) transmit XON threshold
public ushort XoffLim; // 指定在XOFF字符發(fā)送這前接收緩沖區(qū)中可允許的最小字節(jié)數(shù) transmit XOFF threshold
public byte ByteSize; // 指定端口當(dāng)前使用的數(shù)據(jù)位 number of bits/byte, 4-8
public byte Parity; // 指定端口當(dāng)前使用的奇偶校驗(yàn)方法,可能為:EVENPARITY,MARKPARITY,NOPARITY,ODDPARITY 0-4=no,odd,even,mark,space
public byte StopBits; // 指定端口當(dāng)前使用的停止位數(shù),可能為:ONESTOPBIT,ONE5STOPBITS,TWOSTOPBITS 0,1,2 = 1, 1.5, 2
public char XonChar; // 指定用于發(fā)送和接收字符XON的值 Tx and Rx XON character
public char XoffChar; // 指定用于發(fā)送和接收字符XOFF值 Tx and Rx XOFF character
public char ErrorChar; // 本字符用來(lái)代替接收到的奇偶校驗(yàn)發(fā)生錯(cuò)誤時(shí)的值 error replacement character
public char EofChar; // 當(dāng)沒(méi)有使用二進(jìn)制模式時(shí),本字符可用來(lái)指示數(shù)據(jù)的結(jié)束 end of input character
public char EvtChar; // 當(dāng)接收到此字符時(shí),會(huì)產(chǎn)生一個(gè)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, // 要打開(kāi)的串口名稱
uint dwDesiredAccess, // 指定串口的訪問(wèn)方式，一般設(shè)置為可讀可寫方式
int dwShareMode, // 指定串口的共享模式，串口不能共享，所以設(shè)置為0
int lpSecurityAttributes, // 設(shè)置串口的安全屬性，WIN9X下不支持，應(yīng)設(shè)為NULL
int dwCreationDisposition, // 對(duì)于串口通信，創(chuàng)建方式只能為OPEN_EXISTING
int dwFlagsAndAttributes, // 指定串口屬性與標(biāo)志，設(shè)置為FILE_FLAG_OVERLAPPED(重疊I/O操作)，指定串口以異步方式通信
int hTemplateFile // 對(duì)于串口通信必須設(shè)置為NULL
);
[DllImport("coredll.dll")]
private static extern int GetCommState(
int hFile, //通信設(shè)備句柄
ref DCB lpDCB // 設(shè)備控制塊DCB
);
[DllImport("coredll.dll")]
private static extern bool BuildCommDCB(
string lpDef, // 設(shè)備控制字符串
ref DCB lpDCB // 設(shè)備控制塊
);
[DllImport("coredll.dll")]
private static extern bool SetCommState(
int hFile, // 通信設(shè)備句柄
ref DCB lpDCB // 設(shè)備控制塊
);
[DllImport("coredll.dll")]
private static extern bool GetCommTimeouts(
int hFile, // 通信設(shè)備句柄 handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // 超時(shí)時(shí)間 time-out values
);
[DllImport("coredll.dll")]
private static extern bool SetCommTimeouts(
int hFile, // 通信設(shè)備句柄 handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // 超時(shí)時(shí)間 time-out values
);
[DllImport("coredll.dll")]
private static extern int ReadFile(
int hFile, // 通信設(shè)備句柄 handle to file
byte[] lpBuffer, // 數(shù)據(jù)緩沖區(qū) data buffer
int nNumberOfBytesToRead, // 多少字節(jié)等待讀取 number of bytes to read
ref int lpNumberOfBytesRead, // 讀取多少字節(jié) number of bytes read
ref OVERLAPPED lpOverlapped // 溢出緩沖區(qū) overlapped buffer
);
[DllImport("coredll.dll")]
private static extern bool WriteFile(
int hFile, // 通信設(shè)備句柄 handle to file
byte[] lpBuffer, // 數(shù)據(jù)緩沖區(qū) data buffer
int nNumberOfBytesToWrite, // 多少字節(jié)等待寫入 number of bytes to write
ref int lpNumberOfBytesWritten, // 已經(jīng)寫入多少字節(jié) number of bytes written
ref OVERLAPPED lpOverlapped // 溢出緩沖區(qū) 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);
//打開(kāi)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);
// 如果串口沒(méi)有打開(kāi)
if (hComm == INVALID_HANDLE_VALUE)
{
throw (new ApplicationException("非法操作，不能打開(kāi)串口！"));
}
// 設(shè)置通信超時(shí)時(shí)間 SET THE COMM TIMEOUTS.
GetCommTimeouts(hComm, ref ctoCommPort);
ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
ctoCommPort.ReadTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutConstant = 0;
SetCommTimeouts(hComm, ref ctoCommPort);
// 設(shè)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，不能打開(kāi)串口！"));
}
Opened = true;
}
public void Close()
{
if (hComm != INVALID_HANDLE_VALUE)
{
CloseHandle(hComm);
}
}
//讀數(shù)據(jù)
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("串口未打開(kāi)！"));
}
MessageBox.Show("OutBytes.length is :"+OutBytes.Length);
return OutBytes;
}
//來(lái)源自.net compact framework 技術(shù)內(nèi)幕第11章串行通信第347頁(yè)
//用的就是這個(gè)方法來(lái)讀的
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("串口未打開(kāi)！"));
}
else
{
result=objEncoder.GetString(OutBytes,0,BytesToRead);
MessageBox.Show("result is :"+result);
}
}
return result;
}
//這個(gè)方法是把數(shù)據(jù)寫到串口上的，來(lái)源自.net compact framework 技術(shù)內(nèi)幕第11章串行通信第347頁(yè)
//沒(méi)有用到這個(gè)方法暫時(shí)
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("寫成功了");
}
else
{
MessageBox.Show("沒(méi)有成功！!");
}
}
}
// 這個(gè)方法也是寫數(shù)據(jù)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("串口未打開(kāi)！"));
}
}
}
public class HexCon
{
// 把十六進(jìn)制字符串轉(zhuǎn)換成字節(jié)型和把字節(jié)型轉(zhuǎn)換成十六進(jìn)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;
}
}
}
原文: http://blog.csdn.net/zhiyuzhe/archive/2006/12/15/1444313.aspx