Can't seemd to get ReadFile API to work! Returns invalid handle
error?
================================================== =========================
Ok, the visual basic gurus, help!
The following is a diskette class (vb .net) that works find, in that I
can validate a diskette is mounted, dismount it, lock it, unlock it,
get diskette geometry, etc., all with a valid handle from CreateFile
API! I can even position the file pointer, BUT... When I try to
read the disk sector... BANG I get an invaild handle error from the
ReadFile API call? And yes, I am trying to read a Bytes-Per-Sector
size length, i.e. 512. Help!
Option Explicit On
Option Strict On
'
Imports System.Runtime.InteropServices.Marshal
Imports System.Reflection.Assembly
Imports System.Runtime.InteropServices
'
Public Class DisketteClass
'
Public Const DISKETTE_ONE As String = "\\.\A:", _
DISKETTE_TWO As String = "\\.\B:"
Private Const GENERIC_WRITE As Integer = &H40000000, _
GENERIC_READ As Integer = &H80000000
Private Const OPEN_EXISTING As Integer = &H3
Private Const SHARE_WRITE As Integer = &H2, _
SHARE_READ As Integer = &H1
Private Const FILE_BEGIN As Integer = 0, _
FILE_CURRENT As Integer = 1, _
FILE_END As Integer = 2
Private Const ATTRIBUTE_NO_BUFFERING As Integer = &H20000000, _
ATTRIBUTE_SYSTEM As Integer = &H4, _
ATTRIBUTE_NORMAL As Integer = &H80
Private Const FILE_DEVICE_FILE_SYSTEM As Integer = &H9, _
METHOD_BUFFERED As Integer = 0, _
FILE_ANY_ACCESS As Integer = 0, _
FILE_DEVICE_DISK As Integer = &H7
Private Const INVALID_SET_FILE_POINTER As Integer = -1
Private Const IOCTL_DISK_BASE As Integer = FILE_DEVICE_DISK
'
Public Enum DiskettePosition
'
Absolute = 0
Logical = 1
End Enum
'
<StructLayout(LayoutKind.Explicit)> _
Public Structure _LARGE_INTEGER
'
<FieldOffset(0)> Dim theLow As Integer
<FieldOffset(4)> Dim theHigh As Integer
<FieldOffset(0)> Dim theQuad As Long
End Structure
<StructLayout(LayoutKind.Sequential)> _
Public Structure _DISK_GEOMETRY
'
Dim theCylinders As _LARGE_INTEGER, _
theMediaType As MediaType, _
theTracksPerCylinder As Integer, _
theSectorsPerTrack As Integer, _
theBytesPerSector As Integer
End Structure
'
Public Enum DisketteError
' Windows API Tape Error(s)...
Success = 0& ' ERROR_SUCCESS
ReadFault = 30& ' ERROR_READ_FAULT
NotSupported = 50& ' ERROR_NOT_SUPPORTED
WriteProtect = 19& ' ERROR_WRITE_PROTECT
MoreData = 234& ' ERROR_MORE_DATA
InValidFunction = 1& ' ERROR_INVALID_FUNCTION
FileNotFound = 2& ' ERROR_FILE_NOT_FOUND
BadUnit = 20& ' ERROR_BAD_UNIT
WriteFault = 29& ' ERROR_WRITE_FAULT
NotReady = 21& ' ERROR_NOT_READY
CyclicRedundencyCheck = 23& ' ERROR_CRC
End Enum
Public Enum MediaType
'
Unknown
F5_1Pt2_512 ' 5.25", 1.2MB, 512 bytes/sector
F3_1Pt44_512 ' 3.5", 1.44MB, 512 bytes/sector
F3_2Pt88_512 ' 3.5", 2.88MB, 512 bytes/sector
F3_20Pt8_512 ' 3.5", 20.8MB, 512 bytes/sector
F3_720_512 ' 3.5", 720KB, 512 bytes/sector
F5_360_512 ' 5.25", 360KB, 512 bytes/sector
F5_320_512 ' 5.25", 320KB, 512 bytes/sector
F5_320_1024 ' 5.25", 320KB, 1024 bytes/sector
F5_180_512 ' 5.25", 180KB, 512 bytes/sector
F5_160_512 ' 5.25", 160KB, 512 bytes/sector
RemovableMedia ' Removable media other than floppy
FixedMedia ' Fixed hard disk media
F3_120M_512
F3_640_512
F5_640_512
F5_720_512
F3_1Pt2_512
F3_1Pt23_1024
F5_1Pt23_1024
F3_128Mb_512
F3_230Mb_512
F8_256_128
F3_200Mb_512
F3_240M_512
F3_32M_512
End Enum
'
Private Structure DisketteStructure
'
Dim theGeometry As _DISK_GEOMETRY, _
theHandle As IntPtr, _
thePath As String, _
theResult As Integer
End Structure
'
<DllImport("KERNEL32.DLL", _
EntryPoint:="SetFilePointer", _
SetLastError:=True, _
CharSet:=CharSet.Auto, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function SetFilePointer _
(ByVal theHandle As IntPtr, ByVal theLow As Int32, ByRef
theHigh As Int32, ByVal theMode As Int32) As Int32
'
End Function
<DllImport("KERNEL32.DLL", _
EntryPoint:="DeviceIoControl", _
SetLastError:=True, _
CharSet:=CharSet.Auto, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function DeviceIoControl _
(ByVal theHandle As IntPtr, ByVal theCode As Int32, ByVal
theIn As IntPtr, ByVal theInLength As Int32, <Out()> ByVal theOut As
IntPtr, ByVal theOutSize As Int32, ByRef theSize As Int32, ByVal
theOverLapped As IntPtr) As Boolean
'
End Function
<DllImport("KERNEL32.DLL", _
EntryPoint:="CreateFileW", _
SetLastError:=True, _
CharSet:=CharSet.Unicode, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function CreateFile _
(ByVal thePath As String, ByVal theAccess As Integer, ByVal
theMode As Integer, ByVal theAttributes As Integer, ByVal
theDisposition As Integer, ByVal theFlag As Integer, ByVal theTemplate
As Integer) As IntPtr
'
End Function
<DllImport("KERNEL32.DLL", _
EntryPoint:="CloseHandle", _
SetLastError:=True, _
CharSet:=CharSet.Auto, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function CloseHandle _
(ByVal theHandle As IntPtr) As Boolean
'
End Function
<DllImport("KERNEL32.DLL", _
EntryPoint:="ReadFile", _
SetLastError:=True, _
CharSet:=CharSet.Auto, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function ReadFile _
(ByVal theHandle As IntPtr, ByVal theData As Byte(), ByVal
theSize As Integer, ByRef theLength As Integer, ByRef theOverlapped As
Integer) As Boolean
'
End Function
<DllImport("KERNEL32.DLL", _
EntryPoint:="WriteFile", _
SetLastError:=True, _
CharSet:=CharSet.Auto, _
ExactSpelling:=True, _
CallingConvention:=CallingConvention.StdCall)> _
Private Shared Function WriteFile _
(ByVal theHandle As IntPtr, ByVal theData As Byte(), ByVal
theSize As Integer, ByRef theLength As Integer, ByRef theOverlapped As
Integer) As Boolean
'
End Function
Private theDiskette As DisketteStructure
'
Public Sub New(Optional ByVal thePath As String = DISKETTE_ONE)
'
With theDiskette
'
.thePath = thePath
Open()
Geometry()
End With
End Sub
Public Sub Dispose()
'
Close()
End Sub
Public Function Position(ByVal thePosition As Integer, Optional
ByVal theMode As DiskettePosition = DiskettePosition.Logical) As
Boolean
Dim thePositionOrNot As Boolean, _
theDistance As Integer
'
With theDiskette
'
With .theGeometry
'
thePosition = CInt(IIf(theMode <> _
DiskettePosition.Logical, thePosition, thePosition
* .theBytesPerSector))
End With
'
thePosition = SetFilePointer _
(.theHandle, thePosition, theDistance, FILE_BEGIN)
Select Case (thePosition)
Case INVALID_SET_FILE_POINTER
'
thePositionOrNot = False
.theResult = GetLastWin32Error()
Case Else
'
thePositionOrNot = True
End Select
End With
Return (thePositionOrNot)
End Function
Public Function Read(ByVal theData As Byte()) As Boolean
Dim theReadOrNot As Boolean, _
theSize As Integer, _
theLength As Integer
'
With theDiskette
'
theReadOrNot = ReadFile _
(.theHandle, theData, theLength, theSize, Nothing)
Select Case (theReadOrNot And (Not (theLength <>
theSize)))
Case True
'
Case False
'
.theResult = GetLastWin32Error()
theReadOrNot = False
End Select
End With
Return (theReadOrNot)
End Function
Public Function Write(ByVal theData As Byte()) As Boolean
'
End Function
Public Function Geometry() As Boolean
Dim theGeometryOrNot As Boolean, _
theBuffer As IntPtr, _
theSize As Integer, _
theLength As Integer
'
With theDiskette
'
theLength = SizeOf(.theGeometry)
theBuffer = Marshal. _
AllocHGlobal(theLength)
' IOCTL_DISK_GET_DRIVE_GEOMETRY (&H70000)...
theGeometryOrNot = DeviceIoControl(.theHandle,
ControlCode(IOCTL_DISK_BASE, 0, _
METHOD_BUFFERED, FILE_ANY_ACCESS), IntPtr.Zero,
Nothing, theBuffer, theLength, theSize, IntPtr.Zero)
Select Case (theGeometryOrNot)
Case True
'
.theGeometry = CType(Marshal.PtrToStructure _
(theBuffer, GetType(_DISK_GEOMETRY)),
_DISK_GEOMETRY)
Case False
'
.theResult = GetLastWin32Error()
End Select
'
Marshal. _
FreeHGlobal(theBuffer)
End With
End Function
Public Function Open() As Integer
'
With theDiskette
'
.theHandle = CreateFile(.thePath, GENERIC_READ Or
GENERIC_WRITE, _
SHARE_READ Or SHARE_WRITE, Nothing, OPEN_EXISTING,
ATTRIBUTE_NORMAL, Nothing)
If (IsNotHandle(.theHandle)) Then
'
.theResult = GetLastWin32Error()
End If
End With
'
Return (Result)
End Function
Public Function Close() As Integer
'
With theDiskette
'
Select Case (CloseHandle(.theHandle))
Case True
'
.theResult = DisketteError. _
Success
Case False
'
.theResult = GetLastWin32Error()
End Select
.theHandle = Nothing
End With
'
Return (Result)
End Function
Public ReadOnly Property Path() As String
Get
'
With theDiskette
'
Return (.thePath)
End With
End Get
End Property
Public ReadOnly Property Result() As Integer
Get
'
With theDiskette
'
Return (.theResult)
End With
End Get
End Property
Public ReadOnly Property Cylinders() As _LARGE_INTEGER
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theCylinders)
End With
End With
End Get
End Property
Public ReadOnly Property Type() As MediaType
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theMediaType)
End With
End With
End Get
End Property
Public ReadOnly Property BytesPerSector() As Integer
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theBytesPerSector)
End With
End With
End Get
End Property
Public ReadOnly Property SectorsPerTrack() As Integer
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theSectorsPerTrack)
End With
End With
End Get
End Property
Public ReadOnly Property TracksPerCylinder() As Integer
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theTracksPerCylinder)
End With
End With
End Get
End Property
Public ReadOnly Property Size() As Long
Get
'
With theDiskette
'
With .theGeometry
'
Return (.theTracksPerCylinder * _
.theSectorsPerTrack * .theBytesPerSector *
..theCylinders.theQuad)
End With
End With
End Get
End Property
Public Function Mount() As Boolean
'
End Function
Public Function UnMount() As Boolean
Dim theUnMountOrNot As Boolean, _
theSize As Integer
'
With theDiskette
' FSCTL_DISMOUNT_VOLUME...
theUnMountOrNot = DeviceIoControl(.theHandle,
ControlCode(FILE_DEVICE_FILE_SYSTEM, _
8, METHOD_BUFFERED, FILE_ANY_ACCESS), Nothing,
Nothing, Nothing, Nothing, theSize, Nothing)
Select Case (theUnMountOrNot)
Case True
'
Case False
'
.theResult = GetLastWin32Error()
End Select
End With
Return (theUnMountOrNot)
End Function
Public Function Lock() As Boolean
Dim theLockOrNot As Boolean, _
theSize As Integer
'
With theDiskette
' FSCTL_LOCK_VOLUME...
theLockOrNot = DeviceIoControl(.theHandle,
ControlCode(FILE_DEVICE_FILE_SYSTEM, _
6, METHOD_BUFFERED, FILE_ANY_ACCESS), Nothing,
Nothing, Nothing, Nothing, theSize, Nothing)
Select Case (theLockOrNot)
Case True
'
Case False
'
.theResult = GetLastWin32Error()
End Select
End With
Return (theLockOrNot)
End Function
Public Function UnLock() As Boolean
Dim theUnLockOrNot As Boolean, _
theSize As Integer
'
With theDiskette
' FSCTL_UNLOCK_VOLUME...
theUnLockOrNot = DeviceIoControl(.theHandle,
ControlCode(FILE_DEVICE_FILE_SYSTEM, _
7, METHOD_BUFFERED, FILE_ANY_ACCESS), Nothing,
Nothing, Nothing, Nothing, theSize, Nothing)
Select Case (theUnLockOrNot)
Case True
'
Case False
'
.theResult = GetLastWin32Error()
End Select
End With
Return (theUnLockOrNot)
End Function
Public Function IsMount() As Boolean
Dim theIsOrNot As Boolean, _
theSize As Integer
'
With theDiskette
' FSCTL_IS_VOLUME_MOUNTED...
theIsOrNot = DeviceIoControl(.theHandle,
ControlCode(FILE_DEVICE_FILE_SYSTEM, _
10, METHOD_BUFFERED, FILE_ANY_ACCESS), Nothing,
Nothing, Nothing, Nothing, theSize, Nothing)
Select Case (theIsOrNot)
Case True
'
Case False
'
.theResult = GetLastWin32Error()
End Select
End With
Return (theIsOrNot)
End Function
Private Function ControlCode(ByVal theDevice As Integer, ByVal
theFunction As Integer, ByVal theMethod As Integer, ByVal theAccess As
Integer) As Integer
'
Return (CInt(theDevice * (2 ^ 16)) Or CInt _
(theAccess * (2 ^ 14)) Or CInt(theFunction * (2 ^ 2)) Or
theMethod)
End Function
End Class
