c++代码寻找USB00端口并添加打印机-编程知识

USB00*端口的背景

插入USB端口的打印机，安装打印机驱动，在控制面板设备与打印机处的打印机对象上右击，可以看到打印机端口。对于不少型号，这个端口是USB001或USB002之类的。

经观察，这些USB00*端口并不是打印机驱动所创建的。即使不安装打印机驱动，插入此型号的打印机也会创建或者复用USB00*端口。从setupapi.dev.log中可知，端口是在C:\Windows\INF\usbprint.inf的指示下创建的。所谓复用，指的是，若USB001端口已存在并且没有关联上打印机，那么此时插入相关型号打印机，此打印机设备会跟USB001端口绑定起来。

在设备管理器中可以看到USB00*端口和设备的对应关系。这里的USB打印支持的设备还具有硬件ID属性vid、pid。若vid、pid均相同，我认为它们都是同一型号的打印机。

USB00*端口的背景

c++代码寻找USB00*所在的设备

类似于设备管理器，本节的目标是：遍历设备管理器里的设备大类，再找每一个设备，再找设备里的各种属性。直到找到我们关注的vid、pid，然后查看其总线关系里的USB00*编号。

c++ demo

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <Cfgmgr32.h>
#pragma comment(lib, "Cfgmgr32.lib")
#include <SetupAPI.h>
#pragma comment(lib, "SetupAPI.lib")
#include <memory>
using namespace std;//keyseq=1        type=2012       buf=USB\VID_0471&PID_0055&REV_0100
bool jobForThePrinter1(const wchar_t* str, const wchar_t*vid, const wchar_t*pid) {if (_wcsnicmp(vid, str+8, 4)) return false;if (_wcsnicmp(pid, str+17, 4)) return false;return true;
}
//keyseq = 26       type = 2012       buf=USBPRINT\UnknownPrinter\6&1cc6481b&0&USB002
bool jobForThePrinterN(int &usb00n, const wchar_t* str) {if (_wcsnicmp(L"USBPRINT", str, 8)) return false;auto lenStr = wcslen(str);if (_wcsnicmp(L"USB", str+lenStr-6, 3)) return false;usb00n = wcstol(str + lenStr - 3, NULL, 10);return true;
}
int getPropertyFromDevinstWhereVidpid(DEVINST dnDevInst, const wchar_t*vid, const wchar_t*pid) {
#define LENBUF 8192ULONG lenBuf = LENBUF;static BYTE buf[LENBUF];ULONG cnt = 0;auto ret = CM_Get_DevNode_Property_Keys(dnDevInst, NULL, &cnt, 0);if (0 == cnt) return 0;std::unique_ptr<DEVPROPKEY[]> keys(new DEVPROPKEY[cnt]);ret = CM_Get_DevNode_Property_Keys(dnDevInst, keys.get(), &cnt, 0);if (ret != CR_SUCCESS) {fprintf(stderr, "CM_Get_DevNode_Property_Keys FAIL %d\n", ret);return 0;}DEVPROPTYPE type;DWORD i = 0;ret = CM_Get_DevNode_PropertyW(dnDevInst, keys.get()+ i, &type, buf, &lenBuf, 0);if (ret != CR_SUCCESS) {fprintf(stderr, "CM_Get_DevNode_PropertyW FAIL %d\n", ret);return 0;}//如果不是"USB打印支持"，则也跳过if (type != DEVPROP_TYPE_STRING) return 0;wprintf(L"%s\n", buf);if (wcscmp(PTCHAR(buf), L"USB 打印支持")) return 0;++i;for (; i < cnt; ++i) {lenBuf = LENBUF;ret = CM_Get_DevNode_PropertyW(dnDevInst, keys.get()+ i, &type, buf, &lenBuf, 0);printf("keyseq=%d\ttype=%x\t", i, type);//keyseq=1        type=2012       buf=USB\VID_0471&PID_0055&REV_0100//keyseq = 26       type = 2012       buf = USBPRINT\UnknownPrinter\6 & 1cc6481b & 0 & USB002switch (type) {case DEVPROP_TYPE_EMPTY:case DEVPROP_TYPE_NULL:continue;case DEVPROP_TYPE_STRING:wprintf(L"buf=%s\n", buf);break;case DEVPROP_TYPE_UINT32:case DEVPROP_TYPE_UINT64:printf("buf=%uld\n", UINT32(buf));break;case DEVPROP_TYPE_GUID: {GUID guidtmp;memcpy(&guidtmp, buf, sizeof(guidtmp));printf("buf={%x-%x-%x-%s}\n", guidtmp.Data1, guidtmp.Data2, guidtmp.Data3, guidtmp.Data4);}break;case DEVPROP_TYPE_BOOLEAN:if (!buf[0]) printf("buf=false\n");else printf("buf=true\n");break;case 0x2012://DEVPROP_TYPEMOD_LIST & DEVPROP_TYPE_STRING{
#if 1LPTSTR strTmp = LPTSTR(buf);unsigned lenTmp = 0;do {lenTmp = wcslen(strTmp);if (!lenTmp) break;wprintf(L"buf=%s\n", strTmp);strTmp = strTmp + lenTmp + 1;} while (1);
#endifif (1 == i) {if (!jobForThePrinter1((const wchar_t*)buf, vid, pid)) return 0;}int usb00n = 0;if (jobForThePrinterN(usb00n, (const wchar_t*)buf)) {return usb00n;}}break;case 0x1003://DEVPROP_TYPEMOD_ARRAY& DEVPROP_TYPE_BYTE//printf("type=%x\n", type);break;default://wprintf(L"type=%x\tbuf=%s\n", type, buf);break;}}return 0;
}int enum36fcEachDevProperty(LPCWSTR vid, LPCWSTR pid) {static const GUID guid36fc = { 0x36fc9e60, 0xc465, 0x11cf,{0x80, 0x56, 0x44, 0x45, 0x53, 0x54, 0, 0} };HDEVINFO hDevInfo = SetupDiGetClassDevs(&guid36fc, 0, 0, DIGCF_PRESENT);if (hDevInfo == INVALID_HANDLE_VALUE) return 1;SP_DEVINFO_DATA deviceInfoData{ sizeof(SP_DEVINFO_DATA) };for (DWORD i = 0; SetupDiEnumDeviceInfo(hDevInfo, i, &deviceInfoData); ++i) {printf("dev=%d\n", i);int usb00n = getPropertyFromDevinstWhereVidpid(deviceInfoData.DevInst, vid, pid);if (usb00n) {SetupDiDestroyDeviceInfoList(hDevInfo);return usb00n;}}SetupDiDestroyDeviceInfoList(hDevInfo);return 0;
}int WaitUsbPrinterDev(const wchar_t* vid, const wchar_t* pid, int minutes) {int usb00n;int i = 0;do {usb00n = enum36fcEachDevProperty(vid, pid);if (usb00n) return usb00n;Sleep(30000);++i;} while (i <= 4 * minutes);return 0;
}

线索

USB00*端口存在时，可以从注册表中搜寻到，诸如HKLM\SYSTEM\CurrentControlSet\Enum\USBPRINT\UnknownPrinter\8&73672f4&0&USB002\Device Parameters里的数据Portname="USB002"，数据ClassGUID={36fc9e60-c465-11cf-8056-444553540000}。所以我们要用设备安装类相关api来遍历设备。

添加USB00*为端口的打印机对象

原理

主要使用apiAddPrinter。参数三是个PRINTER_INFO_2结构体的指针。根据经验，info2.pPrintProcessor一般都是"winprint"。

c++ demo

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <winspool.h>
#include <memory>
using namespace std;
#include <cstdio>void addprinter(int usb00n, const wchar_t* pDrivername) {WCHAR proc[] = L"winprint";PRINTER_INFO_2W info2 = { 0 };info2.pPrintProcessor = proc;auto len = wcslen(pDrivername);unique_ptr<WCHAR[]> drvname(new WCHAR[len+1]);wcscpy_s(drvname.get(), len+1, pDrivername);info2.pDriverName = drvname.get();WCHAR portname[7];swprintf_s(portname, L"USB%03d", usb00n);info2.pPortName = portname;WCHAR printername[] = L"printername";info2.pPrinterName = printername;auto h = AddPrinter(NULL, 2, reinterpret_cast<LPBYTE>(&info2));if (!h) {const auto err = GetLastError();fwprintf(stderr, L"AddPrinter FAIL %d\n", err);return;}wprintf(L"打印机对象添加成功，名为%s\n", printername);
}

main.cpp和部署脚本

main.cpp

#include <clocale>
#include <cstdio>int WaitUsbPrinterDev(const wchar_t* vid, const wchar_t* pid, int minutes = 3);
void addprinter(int usb00n, const wchar_t* pDrivername);int wmain(int argc, wchar_t** argv) {setlocale(LC_CTYPE, "");if (4 != argc) {wprintf(L"请输入：vid pid \"打印机型号\"\n如：6868 0200 \"GP-58130 Series\"\n");}const wchar_t* vid = argv[1];const wchar_t* pid = argv[2];const wchar_t* model = argv[3];wprintf(L"正在扫描设备管理器，请确保相关打印机连入并开机……\n");int usb00n = WaitUsbPrinterDev(vid, pid);if (!usb00n) {wprintf(L"未见相关打印机连入。请检查vidpid是否正确，打印机是否开机\n");return 0;}wprintf(L"此打印机占用端口USB%03d\n正在添加打印机对象……\n", usb00n);addprinter(usb00n, model);return 0;
}

部署脚本

自动添加打印机对象.vbs

Set ws = CreateObject("Wscript.Shell")
ws.run "C:\AutoAddPrinter.exe 6868 0200 "&chr(34)&"GP-58130 Series"&chr(34)&"",vbhide

readme.txt

部署方法： 1. 编辑镜像时将“AutoAddPrinter.exe”放入C盘根目录。将“自动添加打印机对象.vbs”放入开始菜单的启动目录。

2. 编辑镜像时要删除那个型号的打印机对象

3. 镜像下发到终端上。

4. 虚机运行时，保证打印机已连入并开机。此程序会开机自启，扫描出打印机连上并添加打印机对象。打印机对象名称是newprinter