从二进制文件中读取字节并将该值写入VB6中的另一个二进制文件

Question

我有一个二进制文件，并希望从该文件的特定位置读取值。一旦我有了这个值，我想要将这个值写入位于同一位置的另一个文件中。

例如，我有两个二进制文件A1和B1，现在我想从文件A1中读取一个值，该文件存储在二进制位置0000 003E-0000 0041中。

一旦我有了这个值，就必须在文件B1的相同位置上写入值。

它是 VB6 而不是VBA，我不知道如何从VB6中的特定字节位置读取和写入字节

如果我能在VB6代码中获得适当的解决方案，我将不胜感激。

Answer 1

将此模块添加到一个新的Std项目中，并在以下代码中更改与CopyChunk函数一起使用的源文件名和目标文件名：

Option Explicit

Private Sub Form_Load()
    Dim sError          As String
    
    If Not CopyChunk("D:\TEMP\aaa.src", "D:\TEMP\aaa.dest", _
                Position:=&H3E, _
                Size:=&H41 - &H3E + 1, _
                Error:=sError) Then
        MsgBox "Error copying chunk" & vbCrLf & vbCrLf & sError, vbExclamation
    End If
End Sub

Private Function CopyChunk( _
            SourceFile As String, _
            DestFile As String, _
            ByVal Position As Currency, _
            ByVal Size As Long, _
            Optional Error As String) As Boolean
    Dim pSrc            As stdole.IUnknown
    Dim pDest           As stdole.IUnknown
    Dim baData()        As Byte
    
    On Error GoTo EH
    Set pSrc = StreamOpenFile(SourceFile)
    If pSrc Is Nothing Then
        Error = "Cannot open source file (" & SourceFile & ")"
        GoTo QH
    End If
    Set pDest = StreamOpenFile(DestFile, AlwaysCreate:=False)
    If pDest Is Nothing Then
        Error = "Cannot open destination file (" & DestFile & ")"
        GoTo QH
    End If
    If StreamSeekAbsolute(pSrc, Position) <> Position Then
        Error = "Cannot position source file to " & Position
        GoTo QH
    End If
    If StreamSeekAbsolute(pDest, Position) <> Position Then
        Error = "Cannot position destination file to " & Position
        GoTo QH
    End If
    baData = StreamReadBytes(pSrc, Size)
    If UBound(baData) + 1 <> Size Then
        Error = "Cannot read chunk from source file (" & Size & ")"
        GoTo QH
    End If
    If StreamWriteBytes(pDest, baData) <> Size Then
        Error = "Cannot write chunk to destination file (" & Size & ")"
        GoTo QH
    End If
    '--- success
    CopyChunk = True
QH:
    Exit Function
EH:
    Error = Err.Description
End Function