请见代码分析

#include <windows.h>#include <winioctl.h>#include <stdio.h>#include <initguid.h>#include <setupapi.h>#include <string.h>#define MAX_DEVICE 256wchar_t USBSerial[5][100] = {TEXT("")};int gTag = 0;DEFINE_GUID(UsbClassGuid, 0xa5dcbf10L, 0x6530, 0x11d2, 0x90, 0x1f, 0x00, 0xc0, 0x4f, 0xb9, 0x51, 0xed);// SetupDiGetInterfaceDeviceDetail所需要的输出长度，定义足够大#define INTERFACE_DETAIL_SIZE    (1024)// IOCTL控制码#define IOCTL_STORAGE_QUERY_PROPERTY   CTL_CODE(IOCTL_STORAGE_BASE, 0x0500, METHOD_BUFFERED, FILE_ANY_ACCESS)#pragma comment(lib,"setupapi.lib")//自动关机函数void ExitWindowsCode(){    OSVERSIONINFO   stOSVI;       ZeroMemory(&stOSVI   ,   sizeof   (   OSVERSIONINFO   ))   ;       stOSVI.dwOSVersionInfoSize   =   sizeof   (   OSVERSIONINFO   )   ;       if (!GetVersionEx   (   &stOSVI   ))   return;                   if ( ( VER_PLATFORM_WIN32_NT == stOSVI.dwPlatformId ) && (  4  <= stOSVI.dwMajorVersion ) )       {       HANDLE   hToken;              TOKEN_PRIVILEGES   tkp;              if   (!OpenProcessToken(GetCurrentProcess(),TOKEN_ADJUST_PRIVILEGES   |   TOKEN_QUERY,   &hToken))                return;         // Get the LUID for the shutdown privilege.             LookupPrivilegeValue(NULL,   SE_SHUTDOWN_NAME,   &tkp.Privileges[0].Luid);                 tkp.PrivilegeCount   =   1;   //   one   privilege   to   set             tkp.Privileges[0].Attributes   =   SE_PRIVILEGE_ENABLED;             AdjustTokenPrivileges(hToken,   FALSE,   &tkp,   0,(PTOKEN_PRIVILEGES)NULL,   0);                 if   (GetLastError()   !=   ERROR_SUCCESS)               return;             if   (!ExitWindowsEx(EWX_SHUTDOWN   |   EWX_FORCE|EWX_POWEROFF,   0))               return;            }        else//WIN9X        {   ExitWindowsEx(EWX_SHUTDOWN   |   EWX_FORCE   |   EWX_POWEROFF,   0);//   关机        } }// 根据GUID获得设备路径，用来判断U盘设备// lpGuid: GUID指针// pszDevicePath: 设备路径指针的指针// 返回: 成功得到的设备路径个数，可能不止1个int GetDevicePath(LPGUID lpGuid, LPTSTR* pszDevicePath){    HDEVINFO hDevInfoSet;    //设备信息集句柄；    SP_DEVICE_INTERFACE_DATA ifdata;    PSP_DEVICE_INTERFACE_DETAIL_DATA pDetail;    int nCount;    BOOL bResult;    // 取得一个该GUID相关的设备信息集句柄    hDevInfoSet = ::SetupDiGetClassDevs((LPGUID)&UsbClassGuid,     // class GUID         NULL,                    // 无关键字        NULL,                    // 不指定父窗口句柄        DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);    // 目前存在的设备    // 失败...    if (hDevInfoSet == INVALID_HANDLE_VALUE)    {      return 0;    }    // 申请设备接口数据空间    pDetail = (PSP_DEVICE_INTERFACE_DETAIL_DATA)::GlobalAlloc(LMEM_ZEROINIT, INTERFACE_DETAIL_SIZE);    pDetail->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);    nCount = 0;    bResult = TRUE;    // 设备序号=0,1,2... 逐一测试设备接口，到失败为止    while (bResult)    {        ifdata.cbSize = sizeof(ifdata);        // 枚举符合该GUID的设备接口        bResult = ::SetupDiEnumDeviceInterfaces(            hDevInfoSet,     // 设备信息集句柄            NULL,            // 不需额外的设备描述            lpGuid,          // GUID            (ULONG)nCount,   // 设备信息集里的设备序号            &ifdata);        // 设备接口信息        if (bResult)        {            // 取得该设备接口的细节(设备路径)            bResult = SetupDiGetInterfaceDeviceDetail(                hDevInfoSet,    // 设备信息集句柄                &ifdata,        // 设备接口信息                pDetail,        // 设备接口细节(设备路径)                INTERFACE_DETAIL_SIZE,   // 输出缓冲区大小                NULL,           // 不需计算输出缓冲区大小(直接用设定值)                NULL);          // 不需额外的设备描述            if (bResult)            {                // 复制设备路径到输出缓冲区                wcscpy_s(pszDevicePath[nCount],wcslen(pDetail->DevicePath)+1, pDetail->DevicePath);               // 调整计数值                nCount++;            }        }    }    // 释放设备接口数据空间    ::GlobalFree(pDetail);    // 关闭设备信息集句柄    ::SetupDiDestroyDeviceInfoList(hDevInfoSet);   return nCount;}// 返回U盘设备句柄 hDeviceHANDLE OpenDevice(wchar_t* DevicePath){ HANDLE hDevice;    hDevice = CreateFileW(DevicePath,  GENERIC_READ && GENERIC_WRITE,        FILE_SHARE_READ && FILE_SHARE_WRITE,        NULL,        OPEN_EXISTING,        0,        NULL); return hDevice;}int _stdcall WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd) { int i, nDevice; // nDevice 表示有多少个USB设备 int ndevice = 0; // 表示多少个U盘设备(可进行读写的设备)    wchar_t* szDevicePath[MAX_DEVICE];        // 设备路径 HANDLE hDevice;    // DWORD dwOutBytes; // IOCTL输出数据长度    // 定义一个 PSTORAGE_DEVICE_DESCRIPTOR 变量，存放设备属性    PSTORAGE_DEVICE_DESCRIPTOR DeviceDesc;    // 变量初始化    DeviceDesc=(PSTORAGE_DEVICE_DESCRIPTOR)new BYTE[sizeof(STORAGE_DEVICE_DESCRIPTOR) + 512 - 1];    DeviceDesc->Size = sizeof(STORAGE_DEVICE_DESCRIPTOR) + 512 - 1;    // 分配需要的空间    for (i = 0; i < MAX_DEVICE; i++)    {        szDevicePath[i] = new wchar_t[256];    }    // 取设备路径    nDevice = ::GetDevicePath((LPGUID)&UsbClassGuid, szDevicePath);    // 逐一获取设备信息 for (i = 0; i < nDevice; i++)    {        // 打开设备        hDevice = OpenDevice(szDevicePath[i]);             if (hDevice != INVALID_HANDLE_VALUE)        {   for(int j = 0; j < 4; j++)   {                USBSerial[ndevice][j] = szDevicePath[i][j+12];    }   for(int j = 4; j < 28; j++)            {                USBSerial[ndevice][j] = szDevicePath[i][j+22];             }            //printf("U盘序列号为：");            //wprintf(L"%ws\n", USBSerial[ndevice]);            ndevice ++;                 ::CloseHandle(hDevice);         }      }     // 释放空间    for (i = 0; i < MAX_DEVICE; i++)    {        delete []szDevicePath[i];    }// 文件操作 HANDLE hFile; DWORD nBytesRead = 0, dwBytesWritten = 0;       // 打开文件hFile = CreateFile(TEXT("C:\\Windows\\system32\\USBID.ID"),    // file to open                   GENERIC_READ | GENERIC_WRITE,          // open for reading                   FILE_SHARE_READ | FILE_SHARE_WRITE,       // share for reading                   NULL,                  // default security                   OPEN_EXISTING ,         // existing file only                   FILE_ATTRIBUTE_NORMAL, // normal file                   NULL);                 // no attr. templateif (hFile != INVALID_HANDLE_VALUE){ long nFileSize = GetFileSize(hFile, NULL); if (nFileSize == 0) {  bool flag2 = CloseHandle(hFile);    if(::SetFileAttributes(TEXT("C:\\Windows\\system32\\USBID.ID"),FILE_ATTRIBUTE_NORMAL))  {     if (DeleteFile(TEXT("C:\\Windows\\system32\\USBID.ID")))     {      //MessageBox(NULL,TEXT("oo"),TEXT("oo"),MB_OK);     }  } }}// 打开文件hFile = CreateFile(TEXT("C:\\Windows\\system32\\USBID.ID"),    // file to open                   GENERIC_READ | GENERIC_WRITE,          // open for reading                   FILE_SHARE_READ | FILE_SHARE_WRITE,       // share for reading                   NULL,                  // default security                   OPEN_EXISTING ,         // existing file only                   FILE_ATTRIBUTE_NORMAL, // normal file                   NULL);                 // no attr. templateif (hFile == INVALID_HANDLE_VALUE) {   hFile = CreateFile(TEXT("C:\\Windows\\system32\\USBID.ID"),     // file to create                   GENERIC_READ | GENERIC_WRITE,          // open for writing                   FILE_SHARE_READ | FILE_SHARE_WRITE,                      // do not share                   NULL,                   // default security                   CREATE_ALWAYS,          // overwrite existing                   FILE_ATTRIBUTE_NORMAL | // normal file                   FILE_ATTRIBUTE_NORMAL,   // asynchronous I/O                   NULL);   }else{ if (ndevice < 1)    {     ExitWindowsCode();    }}long nFileSize = GetFileSize(hFile, NULL);wchar_t   *tempbuf =   new   wchar_t[nFileSize]   ; // 读文件内容if (nFileSize == 0) {    // 创建文件，并把序列号写入文件中   hFile = CreateFile(TEXT("C:\\Windows\\system32\\USBID.ID"),     // file to create                   GENERIC_READ | GENERIC_WRITE,          // open for writing                   FILE_SHARE_READ | FILE_SHARE_WRITE,                      // do not share                   NULL,                   // default security                   CREATE_ALWAYS,          // overwrite existing                   FILE_ATTRIBUTE_NORMAL | // normal file                   FILE_ATTRIBUTE_NORMAL,   // asynchronous I/O                   NULL);                  // no attr. template   if (hFile == INVALID_HANDLE_VALUE)     {      return 0;     }   // 把序列号写入文件中   WriteFile(hFile,       USBSerial,       2*wcslen(* USBSerial),       &dwBytesWritten,       NULL);    nFileSize = GetFileSize(hFile, NULL);   if (nFileSize == 0)   {    bool flag1 = CloseHandle(hFile);   }   else   {    if (ndevice < 1)    {     ExitWindowsCode();    }   }}else{   //进入比较序列号   ReadFile(hFile,     tempbuf,     nFileSize,     &nBytesRead,     NULL);   // 比较已经有的序列号与新读的是否相等   for(int i = 0; i< ndevice; i ++)   {    for(int j = 0; j < nFileSize/2; j++)    {     if(tempbuf[j] == USBSerial[i][j])            gTag = 1;     else  {     ExitWindowsCode();  }    }    if(gTag == 1)     break;   }   delete tempbuf;}return 0;}