来自 kernel32 的 vba dll 调用 writefile 创建巨大的文件

我正在尝试在 excel 2010 32 位中使用 VBA7 将一个文本文件附加到另一个文本文件，在 Windows 7 64 位上用于原型设计。一旦成功，我将使用相同的方法将来自多个文件的 wav 数据附加到一起，并修改标题信息以使其与附加的 wav 数据的大小相符。

我遇到的问题是当我调用WriteFile（同步）时，需要很长时间才能完成，原因是它正在向文本文件写入 4 个演出，它应该只写入 20 个字节（大小one.txt） . 出了什么问题，或者我该如何调试？

我在这台机器上可用的工具有限，因为它是由一个大型组织管理的。我只能访问用于编程环境的 VBA。Powershell 和普通命令 shell 实用程序可用。

我做了以下研究：阅读所有 dll 调用的 msdn 文章，设置断点以验证值是否正确，阅读Office 2010 中的 32 位与 64 位兼容性，阅读并理解（主要是）关于将信息传递给 dll 程序的 msdn 文章VB，在 VB 中找到了关于 varptr 和调用 dll 函数的这个很棒的页面，并从 msdn C++ 示例中获得了代码，其中有很多学习。

Private Sub cmdCopy_Click()

    #If Win64 Then
        MsgBox ("Win 64")
    #Else
        MsgBox ("Not win 64 bit") ' Developing on 32-bit excel 2010, windows 7 64 bit
    #End If


    'Dim dummyPtr As SECURITY_ATTRIBUTES ' not used, just changed Createfile declare last parameter type to Any to
    ' allow ByVal 0& to be used
    'dummyPtr = Null

    Dim hFile As LongPtr
    hFile = CreateFile("C:\test\one.txt", GENERIC_READ, 0, ByVal 0&, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, ByVal 0&)
    'hFile = CreateFile("C:\test\one.txt", GENERIC_READ, 0, vbNullString, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, ByVal 0&)
    If hFile = INVALID_HANDLE_VALUE Then
        MsgBox ("Could not open one.txt")
    End If

    Dim hAppend As LongPtr
    hAppend = CreateFile("C:\test\two.txt", FILE_WRITE_DATA, FILE_SHARE_READ, ByVal 0&, _
        OPEN_ALWAYS, _
        FILE_ATTRIBUTE_NORMAL, _
        vbNull) ' no template file
    If hAppend = INVALID_HANDLE_VALUE Then
        MsgBox ("Could not open two.txt")
    End If

    Dim cBuff(4096) As Byte
    Dim dwBytesRead As Long
    Dim dwBytesWritten As Long
    Dim dwPos As Long
    Dim bRet As Boolean
    Dim lRet As Long



    ' not actually a long ptr
    Dim lpBytesRead As Long
    'lpBytesRead = VarPtr(dwBytesRead) ' extraeneous because byref in function declare causes VB to pass a pointer to lpBytesRead

     '    While (ReadFile(hFile, cBuff, Len(cBuff(LBound(cBuff))), ' a way to not hard-code the buffer length in the function call
    lRet = ReadFile(hFile, ByVal VarPtr(cBuff(0)), 4096, _
        lpBytesRead, ByVal 0&)
    Debug.Print ("Outside while loop: Readfile: lret, lpBytesRead: " + CStr(lRet) + ", " + CStr(lpBytesRead))

    While (lRet And lpBytesRead > 0)
        dwPos = SetFilePointer(hAppend, 0, vbNull, FILE_END)
        Debug.Print ("cmdCombine: SetFilePointer: dwPos: " + CStr(dwPos))

        Dim i As Long
        'Print the contents of the buffer from ReadFile
        For i = 0 To lpBytesRead
            Debug.Print Hex(cBuff(i)); "='" & Chr(cBuff(i)) & "'"
        Next

        'bRet = LockFile(hAppend, dwPos, 0, dwBytesRead, 0) 'commented for debugging
        Dim lpBuffPointer As Long
        lpBuffPointer = VarPtr(cBuff(0))
        Dim lpBytesWritten As Long
        lpBytesWritten = VarPtr(dwBytesWritten)
        Dim lpTest As LongPtr
        bRet = WriteFile(hAppend, ByVal VarPtr(cBuff(0)), 20, ByVal lpBytesWritten, ByVal 0&)
        'bRet = WriteFile(hAppend, ByVal VarPtr(cBuff(0)), lpBytesRead, ByVal lpBytesWritten, ByVal 0&)
        'bRet = WriteFile(hAppend, lpBuffPointer, lpBytesRead, lpBytesWritten, ByVal 0&) ' another option for calling
        Debug.Print ("cmdCombine: Writefile: bRet, lpBytesRead, lpBytesWritten: " + _
            CStr(bRet) + " " + CStr(lpBytesRead) + " " + CStr(dwBytesWritten))

        'bRet = UnlockFile(hAppend, dwPos, 0, dwBytesRead, 0)
        lRet = ReadFile(hFile, ByVal VarPtr(cBuff(0)), 4096, _
            lpBytesRead, ByVal 0&)
        Debug.Print ("Readfile: lret, lpBytesRead: " + CStr(lRet) + ", " + CStr(lpBytesRead))
    Wend

    ' TODO: set EOF to the current file pointer location?
    'SetEndOfFile (hAppend)

    CloseHandle (hFile)
    CloseHandle (hAppend)
End Sub

在模块中，我有来自 Win32API_PtrSafe.txt 的声明，修改后允许我为 UDT 传递 Null：

Declare PtrSafe Function WriteFile Lib "kernel32" (ByVal hFile As LongPtr, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, lpOverlapped As Any) As Long
'Declare PtrSafe Function WriteFile Lib "kernel32" (ByVal hFile As LongPtr, lpBuffer As Any, ByVal nNumberOfBytesToWrite As Long, lpNumberOfBytesWritten As Long, lpOverlapped As OVERLAPPED) As Long
Declare PtrSafe Function ReadFile Lib "kernel32" (ByVal hFile As LongPtr, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, lpOverlapped As Any) As Long
'Declare PtrSafe Function ReadFile Lib "kernel32" (ByVal hFile As LongPtr, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, lpOverlapped As OVERLAPPED) As Long
Declare PtrSafe Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As Any, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As LongPtr) As LongPtr
'Declare PtrSafe Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As SECURITY_ATTRIBUTES, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As LongPtr) As LongPtr

Declare PtrSafe Function SetFilePointer Lib "kernel32" (ByVal hFile As LongPtr, ByVal lDistanceToMove As Long, lpDistanceToMoveHigh As Long, ByVal dwMoveMethod As Long) As Long
Declare PtrSafe Function CloseHandle Lib "kernel32" (ByVal hObject As LongPtr) As Long

Declare PtrSafe Function LockFile Lib "kernel32" (ByVal hFile As LongPtr, ByVal dwFileOffsetLow As Long, ByVal dwFileOffsetHigh As Long, ByVal nNumberOfBytesToLockLow As Long, ByVal nNumberOfBytesToLockHigh As Long) As Long
Declare PtrSafe Function UnlockFile Lib "kernel32" (ByVal hFile As LongPtr, ByVal dwFileOffsetLow As Long, ByVal dwFileOffsetHigh As Long, ByVal nNumberOfBytesToUnlockLow As Long, ByVal nNumberOfBytesToUnlockHigh As Long) As Long