C# Signature:
[DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
static extern bool DeviceIoControl(IntPtr hDevice, uint dwIoControlCode,
IntPtr lpInBuffer, uint nInBufferSize,
IntPtr lpOutBuffer, uint nOutBufferSize,
out uint lpBytesReturned, IntPtr lpOverlapped);
VB Signature:
<DllImport("kernel32.dll", ExactSpelling:=True, SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function DeviceIoControl(ByVal hDevice As IntPtr, _
ByVal dwIoControlCode As Int32, ByVal lpInBuffer As IntPtr, _
ByVal nInBufferSize As Int32, ByVal lpOutBuffer As IntPtr, _
ByVal nOutBufferSize As Int32, ByRef lpBytesReturned As Int32, _
ByVal lpOverlapped As System.Threading.NativeOverlapped) As Boolean
End Function
User-Defined Types:
None.
Notes:
hDevice - To retrieve a handle to a volume, call CreateFile with the lpFileName parameter set to a string of the following form: \\.\DriveLetter:
Example:
tHandle = CreateFile("\\.\\C:", FileAccess.Read, FileShare.ReadWrite, IntPtr.Zero, FileMode.Open, 0, IntPtr.Zero)
Tips & Tricks:
This is great for interacting with devices; now perhaps someone can help with the SetupDi calls to actually discover the device handles, etc...? If you are able to conquer it (I wasn't) toss me a mail at dotnet at richardgoodwin dot com
-
Richard:
hDevice
in Handle to the device that is to perform the operation. To obtain a device handle, call the CreateFile function.
Sample Code:
Public ReadOnly Property CardID() As String
Get
Dim dwErrorCode As FarcConstants
Dim dwBytesReceived As Int32
Dim ip As IntPtr = Marshal.AllocHGlobal(13)
Dim erg As String
If DeviceIoControl(hDriver, IOCTL_FARC_GET_CARDID, Nothing, 0, ip, 13, dwBytesReceived, Nothing) Then
erg = Marshal.PtrToStringAnsi(ip)
Marshal.FreeHGlobal(ip)
Else
dwErrorCode = Marshal.GetLastWin32Error
Marshal.FreeHGlobal(ip)
Throw New InvalidOperationException("Get Card ID fails. Errorcode: " & _
dwErrorCode.ToString, New System.ComponentModel.Win32Exception(dwErrorCode))
End If
Return erg
End Get
End Property
Alternative Managed API:
Do you know one? Please contribute it!
