检测com端口代码实现

1：scan

hresult cdevhound::scan(const vector<cstring> &guiinfo, vector<dev_info> &vportinfo)  // scan port
{
	hdevinfo hdevinfo;
	sp_devinfo_data deviceinfodata;
	dword i;
	dev_info epi;

	// create a hdevinfo with all present devices.
	hdevinfo = setupdigetclassdevs((lpguid)&guid_devclass_ports,
		0, // enumerator
		0,
		digcf_present);

	if (hdevinfo == invalid_handle_value)
	{
		// insert error handling here.
		return 1;
	}

	// enumerate through all devices in set.

	deviceinfodata.cbsize = sizeof(sp_devinfo_data);
	for(dword i = 0; setupdienumdeviceinfo(hdevinfo,i,&deviceinfodata); i++)
	{		

		memset( &epi,0,sizeof(epi) );	
		int msgtype = wm_dev_msg;
		tchar szdis[max_path] = {0};
		dword nsize = 0;
		memset( &szdis, 0, max_path);
		dword datat;
		lptstr buffer = null;
		dword buffersize = 0;
		memset( &epi,0,sizeof(epi) );		
		if(false==m_bwork)
		{
			break;
		}
		// 
		// call function with null to begin with, 
		// then use the returned buffer size 
		// to alloc the buffer. keep calling until
		// success or an unknown failure.
		// 
		while (!setupdigetdeviceregistryproperty(
			hdevinfo,
			&deviceinfodata,
			spdrp_friendlyname,
			&datat,
			(pbyte)buffer,
			buffersize,
			&buffersize))
		{
			if (getlasterror() == 
				error_insufficient_buffer)
			{
				// change the buffer size.
				if (buffer) localfree(buffer);
				buffer = (lptstr)localalloc(lptr,buffersize);
			}
			else
			{
				// insert error handling here.
				break;
			}
		}
		setupdigetdeviceregistryproperty( hdevinfo, &deviceinfodata, spdrp_friendlyname, null,(pbyte)epi.szfriendlyname, dev_name_max_len*sizeof(tchar), null);
		// get port description from registry
		setupdigetdeviceregistryproperty( hdevinfo, &deviceinfodata, spdrp_devicedesc, null,(pbyte)epi.szdescription, dev_name_max_len*sizeof(tchar), null);

		hkey hdevkey = setupdiopendevregkey( hdevinfo,&deviceinfodata,dics_flag_global,0,direg_dev,key_read );
		if( invalid_handle_value != hdevkey )
		{	
			// get port name
			dword dwcount = 256;
			regqueryvalueex( hdevkey,_t( "portname" ),null,null,(byte*)epi.szportname,&dwcount );
			regclosekey( hdevkey );
		}

// 		tchar szdis[max_path] = {0};
// 		dword nsize = 0;
		bool bget = setupdigetdeviceinstanceid(hdevinfo, &deviceinfodata, szdis, sizeof(szdis), &nsize);
		if(true==bget)
		{
			tstring strid(szdis);
			tstring strchar(_t("\\"));  
			std::size_t pos = strid.rfind(_t("\\"));
			strchar = strid.substr(0,pos);
			if(guidinfofind(strchar, msgtype,guiinfo))
			{
				pos = strid.find_first_of('&');
				_tcscpy(epi.szvid,strid.substr(0,pos).c_str());
				pos = strid.rfind(_t("\\"));
				strchar = strid.substr(pos+1);
				_tcscpy(epi.szguid,strchar.c_str());
				insertportinfo(epi, false, msgtype,vportinfo);
			}
			else
			{
				continue;
			}
		}


	}

	if(hdevinfo != invalid_handle_value)
	{
		setupdidestroydeviceinfolist(hdevinfo);
		hdevinfo = invalid_handle_value;
	}

    return s_ok;
}

2：detect for one type

uint  cdevhound::houndthreadproc()  //detect for one type port
{
	guid *guiddev = (guid*)&guid_class_port;
	hdevinfo hdevinfo = invalid_handle_value;

	// get port class set
	// note:we use digcf_present flag,so maybe you can see
	// some ports on the device manager,but they are not 
	// enumerated by setupdienumdeviceinterfaces in the do-while
	// loop,because their driver are disabled,no application 
	// can open and use them.

	hdevinfo = setupdigetclassdevs( guiddev,
		null,
		null,
		digcf_present | digcf_deviceinterface
		);
	
	if(hdevinfo == invalid_handle_value) 
	{
		return 0;
	}
	
	sp_device_interface_data ifcdata;
	ifcdata.cbsize = sizeof(sp_device_interface_data);
	
	dword dwindex = 0;
	
	dev_info epi;

	bool binit = true;
	
	// enumerate port and modem class device interfaces
	do
	{
		memset( &epi,0,sizeof(epi) );
		
		if( setupdienumdeviceinterfaces(hdevinfo,null, guiddev, dwindex, &ifcdata) )
		{
			sp_devinfo_data devdata;
			devdata.cbsize = sizeof( sp_devinfo_data );
			
			if( !setupdigetdeviceinterfacedetail( hdevinfo,&ifcdata,null,0,null,&devdata ) )
			{
				if( error_insufficient_buffer != getlasterror() )
				{
					// can not get detail interface info
					continue;
				}
			}
			
			// get friendly name from registry
			setupdigetdeviceregistryproperty( hdevinfo, &devdata, spdrp_friendlyname, null,(pbyte)epi.szfriendlyname, dev_name_max_len*sizeof(tchar), null);
			// get port description from registry
			setupdigetdeviceregistryproperty( hdevinfo, &devdata, spdrp_devicedesc, null,(pbyte)epi.szdescription, dev_name_max_len*sizeof(tchar), null);
			// get class name from registry
			//tchar szclass[epi_max_len];
			//setupdigetdeviceregistryproperty( hdevinfo, &devdata, spdrp_class, null,(pbyte)szclass, epi_max_len*sizeof(tchar), null);
			//epi.ntype = checkdeviceclass( szclass );
			
			hkey hdevkey = setupdiopendevregkey( hdevinfo,&devdata,dics_flag_global,0,direg_dev,key_read );
			if( invalid_handle_value != hdevkey )
			{	
				// get port name
				dword dwcount = dev_name_max_len;
				regqueryvalueex( hdevkey,_t( "portname" ),null,null,(byte*)epi.szportname,&dwcount );
				regclosekey( hdevkey );
			}
			
			// insert to port info array
			tchar szdis[max_path] = {0};
			dword nsize = 0;
			bool bget = setupdigetdeviceinstanceid(hdevinfo, &devdata, szdis, sizeof(szdis), &nsize);
			if(true==bget)
			{
				tstring strid(szdis);
				tstring strchar(_t("\\"));  
				std::size_t pos = strid.rfind(_t("\\"));
				std::size_t posbegin = strid.find_first_of('\\');
				strchar = strid.substr(0,pos);
				dwindex++;
				uses_conversion;
				if(tstring::npos != strchar.find(_t("usb\\vid_1782&pid_4d00")))
				{
					strchar = strchar.substr(posbegin+1,pos);
					_tcscpy(epi.szvid,strchar.c_str());
					pos = strid.rfind(_t("\\"));
					strchar = strid.substr(pos+1);
					tstring strcominfo(epi.szportname);
					tstring strcominfo2 = boost::to_lower_copy(strcominfo);  
					boost::erase_first(strcominfo2, "com");  
					_tcscpy(epi.szguid,strcominfo2.c_str());
#if  0
					string strlog;
					ofstream out("d:\\scanport.log",ios::app);
					strlog = convert<string>(binit);
					out <<"init="<< strlog << "\n";
					out <<  w2a(epi.szdescription) << "\n";
					out << w2a(epi.szfriendlyname)<< "\n";
#endif
					for(size_t  nthreadx=0; nthreadx<m_guidvec.size(); nthreadx++)
					{
						if(m_guidvec[nthreadx]==strcominfo2)
						{
							insertportinfo( epi,nthreadx, binit);
#ifdef _write_port_logfile
							string strthrdxlog;
							string strinitlog;
							strthrdxlog = convert<string>(nthreadx);
							ofstream out("d:\\scanport2.log",ios::app);
							strinitlog = convert<string>(binit);
							out <<"init="<< strinitlog << "\n";
							out << "thread id= " << strthrdxlog << "\n";
#endif

						}
					}
				}

			}
		}
		else
		{
			if( error_no_more_items != getlasterror() )
			{
				dwindex++;
				continue;
			}

			dwindex = 0;
			binit = false;
			clearstate();
			sleep(1);
	
			setupdidestroydeviceinfolist(hdevinfo);
			hdevinfo = invalid_handle_value;
			hdevinfo = setupdigetclassdevs( guiddev,
				null,
				null,
				digcf_present | digcf_deviceinterface
			);

			memset(&ifcdata,0,sizeof(sp_device_interface_data));
			ifcdata.cbsize = sizeof(sp_device_interface_data);
		}
		
	}while( m_bwork && (hdevinfo != invalid_handle_value) );

	if(hdevinfo != invalid_handle_value)
	{
		setupdidestroydeviceinfolist(hdevinfo);
		hdevinfo = invalid_handle_value;
	}
	
	return 0;
}