Question

我需要一个代码来检测CD托盘是打开还是关闭。

我认为这是可能的，因为不久前我发现了以下内容：
http://www.technical-recipes.com/2014/reading-the-status-of-dvd-drives-in-c/

问题是我无法使此代码生效。我在Visual Studio 2015中创建了一个新项目，将代码粘贴到那里并重写了一些（很多）东西。

这是我的代码：

 #include "stdafx.h"
 #include <Windows.h>
 #include <string>
 #include <iostream>
 #include <string>


 #define SCSI_IOCTL_DATA_OUT 0 // Give data to SCSI device (e.g. for writing)
 #define SCSI_IOCTL_DATA_IN 1 // Get data from SCSI device (e.g. for reading)
 #define SCSI_IOCTL_DATA_UNSPECIFIED 2 // No data (e.g. for ejecting)

 #define MAX_SENSE_LEN 18 //Sense data max length 
 #define IOCTL_SCSI_PASS_THROUGH_DIRECT 0x4D014 

 using namespace std;

 typedef unsigned short USHORT;
 typedef unsigned char UCHAR;
 typedef unsigned long ULONG;
 typedef void* PVOID;

 typedef struct _SCSI_PASS_THROUGH_DIRECT
 {
     USHORT Length;
     UCHAR ScsiStatus;
     UCHAR PathId;
     UCHAR TargetId;
     UCHAR Lun;
     UCHAR CdbLength;
     UCHAR SenseInfoLength;
     UCHAR DataIn;
     ULONG DataTransferLength;
     ULONG TimeOutValue;
     PVOID DataBuffer;
     ULONG SenseInfoOffset;
     UCHAR Cdb[16];
 }
 SCSI_PASS_THROUGH_DIRECT, *PSCSI_PASS_THROUGH_DIRECT;

 typedef struct _SCSI_PASS_THROUGH_DIRECT_AND_SENSE_BUFFER
 {
     SCSI_PASS_THROUGH_DIRECT sptd;
     UCHAR SenseBuf[MAX_SENSE_LEN];
 }
 T_SPDT_SBUF;


 // Get the drive letter of the first DVD device encountered
 string GetDvdDriveLetter()
 {
 std::string dvdDriveLetter = "";

 DWORD drives = GetLogicalDrives();
 DWORD dwSize = MAX_PATH;
 char szLogicalDrives[MAX_PATH] = { 0 };
 DWORD dwResult = GetLogicalDriveStrings(dwSize, (LPTSTR)szLogicalDrives);

 // DWORD dwResult = GetLogicalDriveStrings(dwSize, szLogicalDrives);

 if (dwResult > 0 && dwResult <= MAX_PATH)
 {
 char* szSingleDrive = szLogicalDrives;

 while (*szSingleDrive)
 {
 const UINT driveType = GetDriveType((LPTSTR)szSingleDrive);

 if (driveType == 5)
 {
 dvdDriveLetter = szSingleDrive;
 dvdDriveLetter = dvdDriveLetter.substr(0, 2);
 break;
 }

 // Get the next drive
 szSingleDrive += strlen(szSingleDrive) + 1;
 }
 }

 return dvdDriveLetter;
 }

 int GetDvdStatus()
 {
 const std::string dvdDriveLetter = GetDvdDriveLetter();

 if (dvdDriveLetter.empty()) return -1;

 const std::string strDvdPath = "\\\\.\\"
 + dvdDriveLetter;

 HANDLE hDevice; // handle to the drive to be examined 
 int iResult = -1; // results flag
 ULONG ulChanges = 0;
 DWORD dwBytesReturned;
 T_SPDT_SBUF sptd_sb; //SCSI Pass Through Direct variable. 
 byte DataBuf[8]; //Buffer for holding data to/from drive. 

 hDevice = CreateFile((LPTSTR)strDvdPath.c_str(), // drive 
 0, // no access to the drive 
 FILE_SHARE_READ, // share mode 
 NULL, // default security attributes 
 OPEN_EXISTING, // disposition 
 FILE_ATTRIBUTE_READONLY, // file attributes 
 NULL);

 // If we cannot access the DVD drive 
 if (hDevice == INVALID_HANDLE_VALUE)
 {
 return -1;
 }

 // A check to see determine if a DVD has been inserted into the drive only when iResult = 1. 
 // This will do it more quickly than by sending target commands to the SCSI
 iResult = DeviceIoControl((HANDLE)hDevice, // handle to device 
 IOCTL_STORAGE_CHECK_VERIFY2, // dwIoControlCode 
 NULL, // lpInBuffer 
 0, // nInBufferSize 
 &ulChanges, // lpOutBuffer 
 sizeof(ULONG), // nOutBufferSize 
 &dwBytesReturned, // number of bytes returned 
 NULL); // OVERLAPPED structure 

 CloseHandle(hDevice);

 // Don't request the tray status as we often don't need it 
 if (iResult == 1) return 2;

 hDevice = CreateFile((LPTSTR)strDvdPath.c_str(),
 GENERIC_READ | GENERIC_WRITE,
 FILE_SHARE_READ | FILE_SHARE_WRITE,
 NULL,
 OPEN_EXISTING,
 FILE_ATTRIBUTE_READONLY,
 NULL);

 if (hDevice == INVALID_HANDLE_VALUE)
 {
 return -1;
 }

 sptd_sb.sptd.Length = sizeof(SCSI_PASS_THROUGH_DIRECT);
 sptd_sb.sptd.PathId = 0;
 sptd_sb.sptd.TargetId = 0;
 sptd_sb.sptd.Lun = 0;
 sptd_sb.sptd.CdbLength = 10;
 sptd_sb.sptd.SenseInfoLength = MAX_SENSE_LEN;
 sptd_sb.sptd.DataIn = SCSI_IOCTL_DATA_IN;
 sptd_sb.sptd.DataTransferLength = sizeof(DataBuf);
 sptd_sb.sptd.TimeOutValue = 2;
 sptd_sb.sptd.DataBuffer = (PVOID) &(DataBuf);
 sptd_sb.sptd.SenseInfoOffset = sizeof(SCSI_PASS_THROUGH_DIRECT);
 sptd_sb.sptd.Cdb[0] = 0x4a;
 sptd_sb.sptd.Cdb[1] = 1;
 sptd_sb.sptd.Cdb[2] = 0;
 sptd_sb.sptd.Cdb[3] = 0;
 sptd_sb.sptd.Cdb[4] = 0x10;
 sptd_sb.sptd.Cdb[5] = 0;
 sptd_sb.sptd.Cdb[6] = 0;
 sptd_sb.sptd.Cdb[7] = 0;
 sptd_sb.sptd.Cdb[8] = 8;
 sptd_sb.sptd.Cdb[9] = 0;
 sptd_sb.sptd.Cdb[10] = 0;
 sptd_sb.sptd.Cdb[11] = 0;
 sptd_sb.sptd.Cdb[12] = 0;
 sptd_sb.sptd.Cdb[13] = 0;
 sptd_sb.sptd.Cdb[14] = 0;
 sptd_sb.sptd.Cdb[15] = 0;

 ZeroMemory(DataBuf, 8);
 ZeroMemory(sptd_sb.SenseBuf, MAX_SENSE_LEN);

 //Send the command to drive - request tray status for drive 
 iResult = DeviceIoControl((HANDLE)hDevice,
 IOCTL_SCSI_PASS_THROUGH_DIRECT,
 (PVOID)&sptd_sb,
 (DWORD)sizeof(sptd_sb),
 (PVOID)&sptd_sb,
 (DWORD)sizeof(sptd_sb),
 &dwBytesReturned,
 NULL);

 CloseHandle(hDevice);

 if (iResult)
 {
 if (DataBuf[5] == 0) iResult = 0; // DVD tray closed 
 else if (DataBuf[5] == 1) iResult = 1; // DVD tray open 
 else return iResult = 2; // DVD tray closed, media present 
 }

 return iResult;
 }

 int main()
 {
 // Uses the following information to obtain the status of a DVD/CD-ROM drive:
 // 1. GetLogicalDriveStrings() to list all logical drives
 // 2. GetDriveType() to obtain the type of drive
 // 3. DeviceIoControl() to obtain the device status
 //
 switch (GetDvdStatus())
 {
 case 0:
 std::cout << "DVD tray closed, no media" << std::endl;
 break;
 case 1:
 std::cout << "DVD tray open" << std::endl;
 break;
 case 2:
 std::cout << "DVD tray closed, media present" << std::endl;
 break;
 default:
 std::cout << "Drive not ready" << std::endl;
 break;
 }

 std::cout << GetDvdDriveLetter() << std::endl;
 getchar();
 return 0;
 }

现在，项目已经建成，但是当我运行应用程序时，它不会返回任何内容，说“驱动器未就绪”。我无法弄清楚发生了什么。

根据CD托盘的状态，必须采取哪些措施才能获得正确的结果？

Answer 1

好的，我找到了解决方案：在资源视图中，我必须右键单击该项目，然后单击“属性”。在“属性”窗口中，转到“配置属性” - >＆gt;常规并将字符集设置为未设置。这就是全部。解决方案基于：fiddle

检测CD托盘状态

1 个答案: