Need help with CreateFile API function

26 Nov 2006 9:42 PM

Jim Flanagan

Hi...
I am using VB.net Express to experiment with the Win32 API functions
that are available. The current project is an application that will
read the raw sectors of a logical drive so that a CRC-32 calculation can
be performed on all of the bytes of the logical drive. This is my first
experience with the CreateFile function.

Here is the problem(s) that I am having.

Here is my declaration of the function in a separate module.
     Declare Function CreateFile Lib "kernel32" _
     Alias "CreateFileA" ( _
         ByVal lpFileName As String, _
         ByVal dwDesiredAccess As Integer, _
         ByVal dwShareMode As Integer, _
         ByRef lpSecurityAttributes As Integer, _
         ByVal dwCreationDisposition As Integer, _
         ByVal dwFlagsAndAttributes As Integer, _
         ByVal hTemplateFile As Integer) As Integer

Here is how I am calling the function:

Simply trying to open a file for reading...

         hDevice = CreateFile("C:\Autoexec.bat", GENERIC_READ, _
         FILE_SHARE_READ Or FILE_SHARE_WRITE, _
         0%, _
         OPEN_EXISTING, _
         0%, 0%)

Initially, I was having success opening a physical drive using this
function. However, all of a sudden I am now getting a system error:

         "The revision level is unknown."

and the function fails.

I'm stumped. If anyone has any suggestions would be appreciated.
Thanks.
-jim

26 Nov 2006 10:12 PM

Terry Olsen

Here's a program I wrote that makes images of floppy disks, it uses the
CreateFile API. http://boycot.no-ip.com/vb/RawReadWriteFloppy.htm

I used Int32 instead of Integer for types, not sure if that will make a
difference or not, but I used IntPtr for lpSecurityAttributes.

Show quoteHide quote

"Jim Flanagan" <jf***@tampabay.rr.com> wrote in message
news:nTnah.10688$CR6.487@tornado.tampabay.rr.com...
> Hi...
> I am using VB.net Express to experiment with the Win32 API functions that
> are available. The current project is an application that will read the
> raw sectors of a logical drive so that a CRC-32 calculation can be
> performed on all of the bytes of the logical drive. This is my first
> experience with the CreateFile function.
>
> Here is the problem(s) that I am having.
>
>
> Here is my declaration of the function in a separate module.
>     Declare Function CreateFile Lib "kernel32" _
>     Alias "CreateFileA" ( _
>         ByVal lpFileName As String, _
>         ByVal dwDesiredAccess As Integer, _
>         ByVal dwShareMode As Integer, _
>         ByRef lpSecurityAttributes As Integer, _
>         ByVal dwCreationDisposition As Integer, _
>         ByVal dwFlagsAndAttributes As Integer, _
>         ByVal hTemplateFile As Integer) As Integer
>
> Here is how I am calling the function:
>
> Simply trying to open a file for reading...
>
>         hDevice = CreateFile("C:\Autoexec.bat", GENERIC_READ, _
>         FILE_SHARE_READ Or FILE_SHARE_WRITE, _
>         0%, _
>         OPEN_EXISTING, _
>         0%, 0%)
>
> Initially, I was having success opening a physical drive using this
> function. However, all of a sudden I am now getting a system error:
>
>         "The revision level is unknown."
>
> and the function fails.
>
>
> I'm stumped. If anyone has any suggestions would be appreciated.
> Thanks.
> -jim

26 Nov 2006 10:54 PM

Jim Flanagan

> Here's a program I wrote that makes images of floppy disks, it uses the
> CreateFile API. http://boycot.no-ip.com/vb/RawReadWriteFloppy.htm
>
> I used Int32 instead of Integer for types, not sure if that will make a
> difference or not, but I used IntPtr for lpSecurityAttributes.

Terry -
I just tried your method of declaring the CreateFile function and it
appeared to resolve my problem. I *think* the problem was not the Int32
definition, but the IntPtr. Everything seems to work OK now.

Thanks for sharing your code example.
Take care
-jim