学习笔记之----在Qt下的串口读写

      Tags:  linux Qt 串口

 

 

 

 

        这几天一直纠结于Qt下的串口读写，我把疑问和解决过程陆续记录下来，怕以后忘记了嘿嘿。 欢迎大家一起学习分享经验！      

 

       因为Qt没有提供给我们现成的串口类，在Qt下想实现串口读写操作，有两种办法：

       1.自定义串口类

       通常我们都是使用写好的第三方串口类，当然了有linux下与window下两个版本，我是做Linux下开发的，所以这里就先提供Linux下的串口类资源，网上相关的资源很多很多，baidu google一下就好。

                                                                             

 

几个类之间的关系图

 

在Linux下：我们需要

qextserialbase.cpp和qextserialbase.h 以及posix_qextserialport.cpp和posix_qextserialport.h

 

使用查询Polling方式。

 

   代码资源如下：

/** * @file qextserialenumerator.cpp * @author Michał Policht * @see QextSerialEnumerator */ #include "qextserialenumerator.h" #include <objbase.h> #include <initguid.h> #ifdef _TTY_WIN_ //this is serial port GUID #ifndef GUID_CLASS_COMPORT DEFINE_GUID(GUID_CLASS_COMPORT, 0x86e0d1e0L, 0x8089, 0x11d0, 0x9c, 0xe4, 0x08, 0x00, 0x3e, 0x30, 0x1f, 0x73); #endif /* Gordon Schumacher's macros for TCHAR -> QString conversions and vice versa */ #ifdef UNICODE #define QStringToTCHAR(x) (wchar_t*) x.utf16() #define PQStringToTCHAR(x) (wchar_t*) x->utf16() #define TCHARToQString(x) QString::fromUtf16((ushort*)(x)) #define TCHARToQStringN(x,y) QString::fromUtf16((ushort*)(x),(y)) #else #define QStringToTCHAR(x) x.local8Bit().constData() #define PQStringToTCHAR(x) x->local8Bit().constData() #define TCHARToQString(x) QString::fromLocal8Bit((x)) #define TCHARToQStringN(x,y) QString::fromLocal8Bit((x),(y)) #endif /*UNICODE*/ //static QString QextSerialEnumerator::getRegKeyValue(HKEY key, LPCTSTR property) { DWORD size = 0; RegQueryValueEx(key, property, NULL, NULL, NULL, & size); BYTE * buff = new BYTE[size]; if (RegQueryValueEx(key, property, NULL, NULL, buff, & size) == ERROR_SUCCESS) { return TCHARToQStringN(buff, size); delete [] buff; } else { qWarning("QextSerialEnumerator::getRegKeyValue: can not obtain value from registry"); delete [] buff; return QString(); } } //static QString QextSerialEnumerator::getDeviceProperty(HDEVINFO devInfo, PSP_DEVINFO_DATA devData, DWORD property) { DWORD buffSize = 0; SetupDiGetDeviceRegistryProperty(devInfo, devData, property, NULL, NULL, 0, & buffSize); BYTE * buff = new BYTE[buffSize]; if (!SetupDiGetDeviceRegistryProperty(devInfo, devData, property, NULL, buff, buffSize, NULL)) qCritical("Can not obtain property: %ld from registry", property); QString result = TCHARToQString(buff); delete [] buff; return result; } //static void QextSerialEnumerator::setupAPIScan(QList<QextPortInfo> & infoList) { HDEVINFO devInfo = INVALID_HANDLE_VALUE; GUID * guidDev = (GUID *) & GUID_CLASS_COMPORT; devInfo = SetupDiGetClassDevs(guidDev, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE); if(devInfo == INVALID_HANDLE_VALUE) { qCritical("SetupDiGetClassDevs failed. Error code: %ld", GetLastError()); return; } //enumerate the devices bool ok = true; SP_DEVICE_INTERFACE_DATA ifcData; ifcData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA); SP_DEVICE_INTERFACE_DETAIL_DATA * detData = NULL; DWORD detDataSize = 0; DWORD oldDetDataSize = 0; for (DWORD i = 0; ok; i++) { ok = SetupDiEnumDeviceInterfaces(devInfo, NULL, guidDev, i, &ifcData); if (ok) { SP_DEVINFO_DATA devData = {sizeof(SP_DEVINFO_DATA)}; //check for required detData size SetupDiGetDeviceInterfaceDetail(devInfo, & ifcData, NULL, 0, & detDataSize, & devData); //if larger than old detData size then reallocate the buffer if (detDataSize > oldDetDataSize) { delete [] detData; detData = (SP_DEVICE_INTERFACE_DETAIL_DATA *) new char[detDataSize]; detData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA); oldDetDataSize = detDataSize; } //check the details if (SetupDiGetDeviceInterfaceDetail(devInfo, & ifcData, detData, detDataSize, NULL, & devData)) { // Got a device. Get the details. QextPortInfo info; info.friendName = getDeviceProperty(devInfo, & devData, SPDRP_FRIENDLYNAME); info.physName = getDeviceProperty(devInfo, & devData, SPDRP_PHYSICAL_DEVICE_OBJECT_NAME); info.enumName = getDeviceProperty(devInfo, & devData, SPDRP_ENUMERATOR_NAME); //anyway, to get the port name we must still open registry directly :( ??? //Eh... HKEY devKey = SetupDiOpenDevRegKey(devInfo, & devData, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_READ); info.portName = getRegKeyValue(devKey, TEXT("PortName")); RegCloseKey(devKey); infoList.append(info); } else { qCritical("SetupDiGetDeviceInterfaceDetail failed. Error code: %ld", GetLastError()); delete [] detData; return; } } else { if (GetLastError() != ERROR_NO_MORE_ITEMS) { delete [] detData; qCritical("SetupDiEnumDeviceInterfaces failed. Error code: %ld", GetLastError()); return; } } } delete [] detData; } #endif /*_TTY_WIN_*/ //static QList<QextPortInfo> QextSerialEnumerator::getPorts() { QList<QextPortInfo> ports; #ifdef _TTY_WIN_ OSVERSIONINFO vi; vi.dwOSVersionInfoSize = sizeof(vi); if (!::GetVersionEx(&vi)) { qCritical("Could not get OS version."); return ports; } // Handle windows 9x and NT4 specially if (vi.dwMajorVersion < 5) { qCritical("Enumeration for this version of Windows is not implemented yet"); /* if (vi.dwPlatformId == VER_PLATFORM_WIN32_NT) EnumPortsWNt4(ports); else EnumPortsW9x(ports);*/ } else //w2k or later setupAPIScan(ports); #endif /*_TTY_WIN_*/ #ifdef _TTY_POSIX_ qCritical("Enumeration for POSIX systems is not implemented yet."); #endif /*_TTY_POSIX_*/ return ports; }

/*! /class Posix_QextSerialPort /version 1.0.0 /author Stefan Sander /author Michal Policht A cross-platform serial port class. This class encapsulates the POSIX portion of QextSerialPort. The user will be notified of errors and possible portability conflicts at run-time by default - this behavior can be turned off by defining _TTY_NOWARN_ (to turn off all warnings) or _TTY_NOWARN_PORT_ (to turn off portability warnings) in the project. Note that _TTY_NOWARN_ will also turn off portability warnings. */ #include <stdio.h> #include "posix_qextserialport.h" /*! /fn Posix_QextSerialPort::Posix_QextSerialPort() Default constructor. Note that the name of the device used by a QextSerialPort constructed with this constructor will be determined by #defined constants, or lack thereof - the default behavior is the same as _TTY_LINUX_. Possible naming conventions and their associated constants are: /verbatim Constant Used By Naming Convention ---------- ------------- ------------------------ _TTY_WIN_ Windows COM1, COM2 _TTY_IRIX_ SGI/IRIX /dev/ttyf1, /dev/ttyf2 _TTY_HPUX_ HP-UX /dev/tty1p0, /dev/tty2p0 _TTY_SUN_ SunOS/Solaris /dev/ttya, /dev/ttyb _TTY_DIGITAL_ Digital UNIX /dev/tty01, /dev/tty02 _TTY_FREEBSD_ FreeBSD /dev/ttyd0, /dev/ttyd1 _TTY_LINUX_ Linux /dev/ttyS0, /dev/ttyS1 <none> Linux /dev/ttyS0, /dev/ttyS1 /endverbatim This constructor assigns the device name to the name of the first port on the specified system. See the other constructors if you need to open a different port. */ Posix_QextSerialPort::Posix_QextSerialPort() : QextSerialBase() { Posix_File=new QFile(); } /*! /fn Posix_QextSerialPort::Posix_QextSerialPort(const Posix_QextSerialPort&) Copy constructor. */ Posix_QextSerialPort::Posix_QextSerialPort(const Posix_Qex