IOCTL_STORAGE_MEDIA_REMOVAL

The IOCTL_STORAGE_MEDIA_REMOVAL DeviceIoControl operation enables or disables the mechanism that ejects media, for those devices possessing that locking capability.

BOOL DeviceIoControl(
  (HANDLE) hDevice,        // handle to device of interest
  IOCTL_STORAGE_MEDIA_REMOVAL, // dwIoControlCode, control code of
                           // operation to perform
  (LPVOID) lpInBuffer,     // address of input buffer 
  (DWORD) nInBufferSize,   // size, in bytes, of input buffer 
  NULL,                    // lpOutBuffer is not used; must be NULL
  0,                       // nOutBufferSize is not used;
                           // must be zero
  (LPDWORD) lpBytesReturned,   // pointer to variable to receive
                           // output byte count
  (LPOVERLAPPED) lpOverlapped  // pointer to OVERLAPPED structure
                           // for asynchronous operation
);

Parameters

hDevice

Handle to the object on which the operation is to be performed. To obtain a device handle, call the CreateFile function.

dwIoControlCode

Control code for the operation. This value identifies the specific operation to be performed and the type of device on which the operation is to be performed. Use IOCTL_STORAGE_MEDIA_REMOVAL for this operation.

lpInBuffer

Pointer to a buffer that contains a PREVENT_MEDIA_REMOVAL data structure.

A TRUE value for that structure's PreventMediaRemoval member specifies that media removal is prevented (the device is locked). A FALSE value specifies that media removal is allowed.

nInBufferSize

Size, in bytes, of the buffer pointed to by lpInBuffer, which must be large enough to contain a PREVENT_MEDIA_REMOVAL data structure.

lpOutBuffer

Pointer to an output buffer. Not used with this operation. Set to NULL.

nOutBufferSize

Size, in bytes, of the buffer pointed to by lpOutBuffer. Not used with this operation. Set to zero.

lpBytesReturned

Pointer to a DWORD variable.

If lpOverlapped is NULL (nonoverlapped I/O), lpBytesReturned is used internally and cannot be NULL.

If lpOverlapped is not NULL (overlapped I/O), lpBytesReturned can be NULL.

lpOverlapped

Pointer to an OVERLAPPED structure.

If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, this parameter must point to a valid OVERLAPPED structure. In this case, DeviceIoControl is performed as an overlapped (asynchronous) operation. If the device was opened with the FILE_FLAG_OVERLAPPED flag and lpOverlapped is NULL, the function fails in unpredictable ways.

If hDevice was opened without specifying the FILE_FLAG_OVERLAPPED flag, this parameter is ignored and the DeviceIoControl function does not return until the operation has been completed, or until an error occurs.

Return Values

If the operation succeeds, DeviceIoControl returns a nonzero value.

If the operation fails, DeviceIoControl returns a nonzero value. To get extended error information, call GetLastError.

Remarks

The IOCTL_STORAGE_MEDIA_REMOVAL operation is valid only for devices that support removable media.

QuickInfo

  Windows NT: Requires version 4.0 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in winioctl.h.

See Also

Device Input and Output Overview, Device Input and Output Operations, DeviceIoControl, IOCTL_STORAGE_EJECT_MEDIA, IOCTL_STORAGE_LOAD_MEDIA, PREVENT_MEDIA_REMOVAL