form1.frm

FAT硬盘格式读写程序,希望能有所裨益.

    For keer = 1 To 26
        If Left$(strSave, InStr(1, strSave, Chr$(0))) = Chr$(0) Then Exit For
        drvName = Left$(strSave, InStr(1, strSave, Chr$(0)) - 2)
        
        Combo1.AddItem drvName

        strSave = Right$(strSave, Len(strSave) - InStr(1, strSave, Chr$(0)))
    Next 'keer
    Combo1.ListIndex = 1
End Sub

Sub ReadDisk(Disk As String, Sector As Double)
Dim a As String
Dim B As String
Dim tem As String
Dim sPos As String
Dim sVolume As String
Dim sUCDVolume() As Byte
Dim i As Long
Dim lSmallSector As Long
Dim lSectorPerFat As Double
Dim lReservedSector As Long
Dim dDiskBytes As Double
Dim dStartPos As Double

Dim lPosLow As Long
Dim lPosHigh As Long

'Dim lAllSector As Double

Dim lSectorPerFat32 As Double

Const S0 = "0000000000"
ReDim sUCDVolume(21)
    Picture1.Cls
    Picture1.ForeColor = vbBlue
    TextOut Picture1.hdc, 30, 5, "Offset", Len("Offset")
    For Log_Col = 0 To 15
        
        a = Hex$(Log_Col)                          '改成直接用16進制表示更好
        TextOut Picture1.hdc, 20 * Log_Col + 90, 5, a, 1& 'Len(a)
    Next

    Picture1.ForeColor = vbRed
    Picture1.Line (0, 18)-(700, 18)
    Picture1.Line (410, 0)-(410, 900)
    Picture1.Line (80, 0)-(80, 900)                            '增加一根竖线

    ReDim Byte_data(511)
 
'    On Error GoTo 10

'----------------------------------------------
    OpenDisk "\\.\" & Disk
'    ReadDiskbyPos Byte_data(), 512 * Sector, 512
    ReadDiskbySector Byte_data(), Sector, 1
    CloseDisk
'----------------------------------------------

    For Log_Row = 0 To 31

        '以下三行是增加偏移量表示
        'dStartPos
        lPosHigh = Int((Log_Row * 16 + Sector * 512) / OFFSET_4)
        lPosLow = UnsignedToLong(Log_Row * 16 + Sector * 512 - lPosHigh * OFFSET_4)
'        a = Hex$(Log_Row * 16 + Sector * 512)
        a = Hex$(lPosLow)
        B = Hex$(lPosHigh)
        a = B & a
        sPos = Left$(S0, 10 - Len(a)) & a
        Picture1.ForeColor = vbBlue
        TextOut Picture1.hdc, 10, 15 * Log_Row + 20, sPos, Len(sPos)
        Picture1.ForeColor = &H0&
        For Log_Col = 0 To 15

            If Byte_data(Log_Row * 16 + Log_Col) < 16 Then
                tem = "0" & Hex(Byte_data(Log_Row * 16 + Log_Col))
            Else
                tem = Hex(Byte_data(Log_Row * 16 + Log_Col))
            End If

            TextOut Picture1.hdc, 20 * Log_Col + 90, 15 * Log_Row + 20, tem, &O2

            If Byte_data(Log_Row * 16 + Log_Col) < &H20 Then
                tem2(Log_Col) = &H2E
            Else
                tem2(Log_Col) = Byte_data(Log_Row * 16 + Log_Col)
            End If

            

        Next
        tem1(0) = StrConv(tem2(), vbUnicode)
        TextOut Picture1.hdc, 20 * 16 + 100, 15 * Log_Row + 20, tem1(0), 16

    Next
    
    Me.Caption = "当前磁盘：" & Combo1.Text
    
    If Sector <> 0 Then Exit Sub
    Command2.Enabled = True
    If Byte_data(1) = &H3C Then

       '得到OEMID
       For i = 0 To 7
           sUCDVolume(2 * i) = Byte_data(i + 3)
       Next
       sVolume = sUCDVolume                       '在VB中，把数组变成Unicode格式，可以直接把数组与字符串等起来
       sVolume = Trim(Left(sVolume, InStr(1, sVolume, Chr$(0), vbTextCompare)))
       Label19.Caption = sVolume
       For i = 0 To 7
          sUCDVolume(2 * i) = 0     '恢复为0
       Next
       '得到每扇区字节数
       pBytesInInteger(0) = Byte_data(&HB)
       pBytesInInteger(1) = Byte_data(&HC)
       Label3.Caption = Str$(lPublicInt)
       '得到每簇扇区数
       Label5.Caption = Str$(Byte_data(&HD))
       'FAT 表个数
       Label12.Caption = Str$(Byte_data(&H10))
       '得到根目录项数
       pBytesInInteger(0) = Byte_data(&H11)
       pBytesInInteger(1) = Byte_data(&H12)
       Label21.Caption = Str$(lPublicInt)
       '得到小扇区数
       pBytesInInteger(0) = Byte_data(&H13)
       pBytesInInteger(1) = Byte_data(&H14)
       lSmallSector = IntToUnsigned(lPublicInt)
       Label25.Caption = Str$(lSmallSector)
       '得到媒体描述符
       Label23.Caption = Str$(Byte_data(&H15))
       'FAT 表占用扇区数
       pBytesInInteger(0) = Byte_data(&H16)
       pBytesInInteger(1) = Byte_data(&H17)
'       lSectorPerFat = lPublicInt
       Label9.Caption = Str$(IntToUnsigned(lPublicInt))
       '得到大扇区数
       pBytesInLong(0) = Byte_data(&H20)
       pBytesInLong(1) = Byte_data(&H21)
       pBytesInLong(2) = Byte_data(&H22)
       pBytesInLong(3) = Byte_data(&H23)
       lAllSector = LongToUnsigned(lPublicLong)
       Label27.Caption = Str$(lAllSector)
       '得到总扇区数
       If lSmallSector = 0 Then
          Label7.Caption = Str$(lAllSector)
       Else
          lAllSector = lSmallSector
          Label7.Caption = Str$(lAllSector)
       End If
       VS1.Max = lAllSector
       '得到隐藏扇区数
       pBytesInLong(0) = Byte_data(&H1C)
       pBytesInLong(1) = Byte_data(&H1D)
       pBytesInLong(2) = Byte_data(&H1E)
       pBytesInLong(3) = Byte_data(&H1F)
       Label15.Caption = Str$(LongToUnsigned(lPublicLong))
       '保留扇区数
       pBytesInInteger(0) = Byte_data(&HE)
       pBytesInInteger(1) = Byte_data(&HF)
'       lReservedSector = IntToUnsigned(lPublicInt)
'       Label35.Caption = Str$(lReservedSector)
       Label35.Caption = Str$(IntToUnsigned(lPublicInt))
       '得到卷序号
       pBytesInLong(0) = Byte_data(&H43)
       pBytesInLong(1) = Byte_data(&H44)
       pBytesInLong(2) = Byte_data(&H45)
       pBytesInLong(3) = Byte_data(&H46)
       Label29.Caption = Str$(LongToUnsigned(lPublicLong))
       '得到卷标
       For i = 0 To 10
           sUCDVolume(2 * i) = Byte_data(&H2B + i) '2b
       Next
       sVolume = sUCDVolume                       '在VB中，把数组变成Unicode格式，可以直接把数组与字符串等起来
       Label31.Caption = sVolume
       For i = 0 To 10
          sUCDVolume(2 * i) = 0     '恢复为0
       Next
       '文件系统类型
       For i = 0 To 7
           sUCDVolume(2 * i) = Byte_data(&H36 + i) '36
       Next
       sVolume = sUCDVolume
       sVolume = Trim(Left(sVolume, InStr(1, sVolume, Chr$(0), vbTextCompare)))
       Label33.Caption = sVolume
       '磁盘字节数
       '磁盘字节数 = (总扇区数 - FAT 表占用扇区数 * FAT 表个数 - 保留扇区数) * 得到每扇区字节数
       
       dDiskBytes = lAllSector - lSectorPerFat * Byte_data(&H10) - lReservedSector
       Label11.Caption = dDiskBytes * 512 & "字节" & vbCrLf & "约" & CLng(dDiskBytes * 512 / 1024 / 1024) & "M"
    ElseIf Byte_data(1) = &H58 Then
       '得到OEMID
       For i = 0 To 7
           sUCDVolume(2 * i) = Byte_data(i + 3)
       Next
       sVolume = sUCDVolume                       '在VB中，把数组变成Unicode格式，可以直接把数组与字符串等起来
       sVolume = Trim(Left(sVolume, InStr(1, sVolume, Chr$(0), vbTextCompare)))
       Label19.Caption = sVolume
       For i = 0 To 7
          sUCDVolume(2 * i) = 0     '恢复为0
       Next
       '得到每扇区字节数
       pBytesInInteger(0) = Byte_data(&HB)
       pBytesInInteger(1) = Byte_data(&HC)
       Label3.Caption = Str$(lPublicInt)
       '得到每簇扇区数
       Label5.Caption = Str$(Byte_data(&HD))
       'FAT 表个数
       Label12.Caption = Str$(Byte_data(&H10))
       '得到根目录项数
       pBytesInInteger(0) = Byte_data(&H11)
       pBytesInInteger(1) = Byte_data(&H12)
       Label21.Caption = Str$(lPublicInt)
       '得到小扇区数
       pBytesInInteger(0) = Byte_data(&H13)
       pBytesInInteger(1) = Byte_data(&H14)
       lSmallSector = IntToUnsigned(lPublicInt)
       Label25.Caption = Str$(lSmallSector)
       '得到媒体描述符
       Label23.Caption = Str$(Byte_data(&H15))
       'FAT 表占用扇区数
       pBytesInLong(0) = Byte_data(&H24)
       pBytesInLong(1) = Byte_data(&H25)
       pBytesInLong(2) = Byte_data(&H26)
       pBytesInLong(3) = Byte_data(&H27)
       lSectorPerFat32 = LongToUnsigned(lPublicLong)
       Label9.Caption = Str$(lSectorPerFat32)
       '得到大扇区数
       pBytesInLong(0) = Byte_data(&H20)
       pBytesInLong(1) = Byte_data(&H21)
       pBytesInLong(2) = Byte_data(&H22)
       pBytesInLong(3) = Byte_data(&H23)
       lAllSector = LongToUnsigned(lPublicLong)
       Label27.Caption = Str$(lAllSector)
       '得到总扇区数
       Label7.Caption = Str$(lAllSector)
       VS1.Max = lAllSector
       '得到隐藏扇区数
       pBytesInLong(0) = Byte_data(&H1C)
       pBytesInLong(1) = Byte_data(&H1D)
       pBytesInLong(2) = Byte_data(&H1E)
       pBytesInLong(3) = Byte_data(&H1F)
       Label15.Caption = Str$(LongToUnsigned(lPublicLong))
       '保留扇区数
       pBytesInInteger(0) = Byte_data(&HE)
       pBytesInInteger(1) = Byte_data(&HF)
       lReservedSector = IntToUnsigned(lPublicInt)
       Label35.Caption = Str$(lReservedSector)
       '得到卷序号
       pBytesInLong(0) = Byte_data(&H27)
       pBytesInLong(1) = Byte_data(&H28)
       pBytesInLong(2) = Byte_data(&H29)
       pBytesInLong(3) = Byte_data(&H2A)
       Label29.Caption = Str$(LongToUnsigned(lPublicLong))
       '得到卷标
       For i = 0 To 10
           sUCDVolume(2 * i) = Byte_data(&H47 + i)
       Next
       sVolume = sUCDVolume                       '在VB中，把数组变成Unicode格式，可以直接把数组与字符串等起来
       Label31.Caption = sVolume
       For i = 0 To 10
          sUCDVolume(2 * i) = 0     '恢复为0
       Next
       '文件系统类型
       For i = 0 To 7
           sUCDVolume(2 * i) = Byte_data(&H52 + i)
       Next
       sVolume = sUCDVolume
       sVolume = Trim(Left(sVolume, InStr(1, sVolume, Chr$(0), vbTextCompare)))
       Label33.Caption = sVolume
       '磁盘字节数
       '磁盘字节数 = (总扇区数 - FAT 表占用扇区数 * FAT 表个数 - 保留扇区数) * 得到每扇区字节数
       
       dDiskBytes = lAllSector - lSectorPerFat32 * Byte_data(&H10) - lReservedSector
       Label11.Caption = dDiskBytes * 512 & "字节" & vbCrLf & "约" & CLng(dDiskBytes * 512 / 1024 / 1024) & "M"
    Else
       Exit Sub
    End If
Exit Sub
10
    If Err.Number = 52 Then Me.Caption = "错误号：" & Err.Number & vbCrLf & Err.Description
    
    Label3.Caption = "": Label5.Caption = "": Label7.Caption = "": Label9.Caption = ""
    Label12.Caption = "": Label15.Caption = "": Label11.Caption = ""
    
End Sub

Private Sub Form_Unload(Cancel As Integer)
  CopyMemory ByVal VarPtrArray(pBytesInLong), 0&, 4
  CopyMemory ByVal VarPtrArray(pBytesInInteger), 0&, 4
End Sub

Private Function LongToUnsigned(Value As Long) As Double
        If Value < 0 Then
          LongToUnsigned = Value + OFFSET_4
        Else
          LongToUnsigned = Value
        End If
End Function

Private Function IntToUnsigned(Value As Integer) As Long
        If Value < 0 Then
          IntToUnsigned = Value + OFFSET_2
        Else
          IntToUnsigned = Value
        End If
End Function




'
Private Sub VS1_Change(Value As Currency)
Call ReadDisk(Combo1.Text, VS1.Value)
Label17.Caption = VS1.Value
End Sub