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CD / DVD Tray Locker

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4.86/5 (21 votes)
13 Jan 2011CPOL1 min read 31.1K   20   7
How to prevent a CD/DVD drive from being opened.

Overview


A few days ago (at the time of writing), someone on the C# forum asked how to lock the CD drive. I thought this was an interesting problem that could be useful if writing burning software or something, and this is the solution.

How To Do It


It requires PInvoke to use three kernel32.dll functions.



We also need to define the SECURITY_ATTRIBUTES structure. Although we don't actually use any of the parameters, we need to pass a default instance of this.

The Code


C#
public static class CDTrayLocker
{
    public static bool Lock(string driveLetter)
    {
        return ManageLock(driveLetter, true);
    }
    public static bool Unlock(string driveLetter)
    {
        return ManageLock(driveLetter, false);
    }

    private static bool ManageLock(string driveLetter, bool lockDrive)
    {
        bool result = false;
        string fileName = string.Format(@"\\.\{0}:", driveLetter);
        SECURITY_ATTRIBUTES securityAttributes = new SECURITY_ATTRIBUTES();
        IntPtr deviceHandle = CreateFile(
            fileName,
            GENERIC_READ,
            FILE_SHARE_READ | FILE_SHARE_WRITE,
            ref securityAttributes,
            OPEN_EXISTING,
            FILE_ATTRIBUTE_NORMAL,
            IntPtr.Zero);

        if (deviceHandle != INVALID_HANDLE_VALUE)
        {
            IntPtr outBuffer;
            int bytesReturned;
            NativeOverlapped overlapped = new NativeOverlapped();
            result = DeviceIoControl(
                deviceHandle,
                IOCTL_STORAGE_MEDIA_REMOVAL,
                ref lockDrive,
                1,
                out outBuffer,
                0,
                out bytesReturned,
                ref overlapped);
            CloseHandle(deviceHandle);
        }
        return result;
    }

    // http://msdn.microsoft.com/en-us/library/aa379560(VS.85).aspx
    [StructLayout(LayoutKind.Sequential)]
    private struct SECURITY_ATTRIBUTES
    {
        int nLength;
        IntPtr lpSecurityDescriptor;
        bool bInheritHandle;
    }

    private const int FILE_SHARE_READ = 0x00000001;
    private const int FILE_SHARE_WRITE = 0x00000002;
    private const uint GENERIC_READ = 0x80000000;
    private const int OPEN_EXISTING = 3;
    private const int FILE_ATTRIBUTE_NORMAL = 0x80;
    private static readonly IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
    private const int IOCTL_STORAGE_MEDIA_REMOVAL = 0x2D4804;

    // http://msdn.microsoft.com/en-us/library/aa363858(VS.85).aspx
    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern IntPtr CreateFile(
        string lpFileName,
        uint dwDesiredAccess,
        int dwShareMode,
        ref SECURITY_ATTRIBUTES lpSecurityAttributes,
        int dwCreationDisposition,
        int dwFlagsAndAttributes,
        IntPtr hTemplateFile);

    // http://msdn.microsoft.com/en-us/library/aa363216(VS.85).aspx
    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool DeviceIoControl(
        IntPtr hDevice,
        int dwIoControlCode,
        ref bool lpInBuffer,
        int nInBufferSize,
        out IntPtr lpOutBuffer,
        int nOutBufferSize,
        out int lpBytesReturned,
        ref NativeOverlapped lpOverlapped);

    // http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx
    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool CloseHandle(
        IntPtr hObject);
}


To use this, simply call Lock or Unlock passing the letter of the required drive.

C#
// Where "D" is your drive letter!
CDTrayLocker.Lock("D");
// Do your thing
CDTrayLocker.Unlock("D");


Points to Note


If you lock a drive n times, you will need to unlock it n times too.

It works under Vista without elevation!

Edit: I haven't had time to look into the reasons why, but I got a Stack error using .NET 4.0. I recompiled using 2.0 and it worked perfectly. If I find the reason I will update here.
Updated with changes to accommodate changes with .NET 4.0

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
CEO Dave Meadowcroft
United Kingdom United Kingdom
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Comments and Discussions

 
GeneralReason for my vote of 5 Reason for my vote 5 it's very usef... Pin
RaviRanjanKr16-Jan-11 2:46
professionalRaviRanjanKr16-Jan-11 2:46 
GeneralThanks. I will need this! Pin
Dr.Walt Fair, PE13-Jan-11 14:18
professionalDr.Walt Fair, PE13-Jan-11 14:18 
GeneralReason for my vote of 5 Good Article. Pin
Dalek Dave13-Jan-11 10:36
professionalDalek Dave13-Jan-11 10:36 
GeneralReason for my vote of 5 Hi Dave. Well done. Except for the s... Pin
Luc Pattyn13-Jan-11 6:43
sitebuilderLuc Pattyn13-Jan-11 6:43 
Reason for my vote of 5
Hi Dave. Well done. Except for the stack issue of course. Laugh | :laugh:
GeneralReason for my vote of 5 very nice Pin
Аslam Iqbal13-Jan-11 3:06
professionalАslam Iqbal13-Jan-11 3:06 
GeneralNice code...i had been looking for this! Great code. Thanks. Pin
GPUToaster™23-May-10 20:01
GPUToaster™23-May-10 20:01 
QuestionOnly works when no media in drive? Pin
rdavisunr20-Apr-11 14:02
rdavisunr20-Apr-11 14:02 

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