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好的，我在这里可能有点偏离基础，但我想做的是使用 GetOpenFileName 的 API 调用的宽 (Unicode) 版本来返回多个文件的列表。

现在，我要这样做的原因是：选择多个文件时，文件名的总字符数限制取决于函数的版本。
•ANSI：32k 限制
•Unicode：无限制

从深埋在我的网络中的目录中返回大量文件可能会很快超过 ANSI 32k 字符的限制。

所以，我所做的是使用我的工作 ANSI 声明函数，并将所有string声明的变量替换为lngptr. 然后，在我需要为这些赋值的地方，我使用了该StrPtr()函数来转换字符串值。

现在，当我尝试调用此函数时，它到达了调用 Declared 函数的部分，它lReturn = GetOpenFileNameU(OpenFile)实际上并没有做任何事情！没有错误，什么都没有——只是越过那条线，什么也没有发生。我做错什么了？？

这就是我现在的位置：

Option Explicit
'***NOTE: _
    This class object requires the following references: _
        <NONE>

'Declare the windows API function for GetOpenFileNameA
'MSDN Reference: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646927(v=vs.85).aspx
Public Declare PtrSafe Function GetOpenFileNameU Lib "comdlg32.dll" Alias "GetOpenFileNameW" (pOpenfilename As OPENFILENAME) As Long

Public Const OFN_ALLOWMULTISELECT As Long = &H200
Public Const OFN_CREATEPROMPT As Long = &H2000
Public Const OFN_ENABLEHOOK As Long = &H20
Public Const OFN_ENABLETEMPLATE As Long = &H40
Public Const OFN_ENABLETEMPLATEHANDLE As Long = &H80
Public Const OFN_EXPLORER As Long = &H80000
Public Const OFN_EXTENSIONDIFFERENT As Long = &H400
Public Const OFN_FILEMUSTEXIST As Long = &H1000
Public Const OFN_HIDEREADONLY As Long = &H4
Public Const OFN_LONGNAMES As Long = &H200000
Public Const OFN_NOCHANGEDIR As Long = &H8
Public Const OFN_NODEREFERENCELINKS As Long = &H100000
Public Const OFN_NOLONGNAMES As Long = &H40000
Public Const OFN_NONETWORKBUTTON As Long = &H20000
Public Const OFN_NOREADONLYRETURN As Long = &H8000& '*see comments
Public Const OFN_NOTESTFILECREATE As Long = &H10000
Public Const OFN_NOVALIDATE As Long = &H100
Public Const OFN_OVERWRITEPROMPT As Long = &H2
Public Const OFN_PATHMUSTEXIST As Long = &H800
Public Const OFN_READONLY As Long = &H1
Public Const OFN_SHAREAWARE As Long = &H4000
Public Const OFN_SHAREFALLTHROUGH As Long = 2
Public Const OFN_SHAREWARN As Long = 0
Public Const OFN_SHARENOWARN As Long = 1
Public Const OFN_SHOWHELP As Long = &H10
Public Const OFN_ENABLESIZING As Long = &H800000
Public Const OFS_MAXPATHNAME As Long = 260

'Create a custom type that matches the OPENFILENAME structure
'MSDN reference: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646839(v=vs.85).aspx
Public Type OPENFILENAME
    lStructSize As Long
    hwndOwner As LongPtr
    hInstance As LongPtr
    lpstrFilter As LongPtr
    lpstrCustomFilter As LongPtr
    nMaxCustFilter As Long
    nFilterIndex As Long
    lpstrFile As LongPtr
    nMaxFile As Long
    lpstrFileTitle As LongPtr
    nMaxFileTitle As Long
    lpstrInitialDir As LongPtr
    lpstrTitle As LongPtr
    flags As Long
    nFileOffset As Integer
    nFileExtension As Integer
    lpstrDefExt As LongPtr
    lCustData As Long
    lpfnHook As LongPtr
    lpTemplateName As LongPtr
End Type


'OFS_FILE_OPEN_FLAGS:
'Can view explanation of flags here on the MSDN reference: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646839(v=vs.85).aspx
Public Const OFS_FILE_OPEN_FLAGS = _
                OFN_EXPLORER Or _
                OFN_LONGNAMES Or _
                OFN_CREATEPROMPT Or _
                OFN_NODEREFERENCELINKS

'Windows version constants
Private Const VER_PLATFORM_WIN32_NT As Long = 2
Private Const OSV_LENGTH As Long = 76
Private Const OSVEX_LENGTH As Long = 88
Public OSV_VERSION_LENGTH As Long

Public Const WM_INITDIALOG As Long = &H110
Private Const SW_SHOWNORMAL As Long = 1


Public Function BrowseForFile(strTitle As String, myFilter As String, Optional initialDir As String = "") As String
'This function allows you to browse for files and returns a string containing the files selected

'Declare variables
    Dim OpenFile    As OPENFILENAME
    Dim lReturn     As Long
    Dim strFile     As String


'Set the file type filter
    OpenFile.lpstrFilter = StrPtr(myFilter)

'Set the filter index.  This is the order of the filters available to select from in the dialog.  1= the first in the list (and currently active)
    OpenFile.nFilterIndex = 1

'Set the handle to the window that owns the dialog box
    OpenFile.hwndOwner = 0

'lpstrFile is a pointer to a string which contains the current directory followed by list of file names selected. _
'Create an empty string to use as buffer, it needs to be at least 256 chars plus a terminating NULL char
    strFile = String(257, 0)
'Pass the buffer string to the pointer
    OpenFile.lpstrFile = StrPtr(strFile)

'The size of nMaxFile = the size, in characters, of the string pointed to by lpstrFile (less one NULL character at the end)
'The size of lStructSize = The length, in bytes, of the structure. Use size of (OPENFILENAME) for this parameter.

'BEFORE we can set the above two properties, we need to heck which version of VBA we are working with (SW uses VBA7, Office uses VBA6) _
 The # indiicates preprocessor command, which is processed prior to compilation, which ensures that the code compiles per the correct platform
        #If VBA7 Then
        'When environment is VBA7, use LenB (binary compare)
            OpenFile.nMaxFile = LenB(strFile) - 1
            OpenFile.lStructSize = LenB(strFile)
        #Else
        'When environment is anything else, use Len (text compare)
            OpenFile.nMaxFile = Len(strFile) - 1
            OpenFile.lStructSize = Len(strFile)
        #End If

'This points to a string containing just the file name and extension (without path info), whereas lpstrFile contains the path info also.
    OpenFile.lpstrFileTitle = OpenFile.lpstrFile
'This is to lpstrFileTile what nMaxFile is to lpstrFile
    OpenFile.nMaxFileTitle = OpenFile.nMaxFile

    'Check if the calling procedure specified a starting directory
        If initialDir <> "" Then OpenFile.lpstrInitialDir = StrPtr(StrConv(initialDir, vbUnicode))

'This will be the title of the window dialog, and is an argument that must be passed by the calling procedure
    OpenFile.lpstrTitle = StrPtr(StrConv(strTitle, vbUnicode))

'Flags control how the window looks and acts. _
'Can view explanation of flags here on the MSDN reference: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646839(v=vs.85).aspx
    OpenFile.flags = OFS_FILE_OPEN_FLAGS + OFN_ALLOWMULTISELECT

'Call the windows API function we delcared and get the return when it completes.
    lReturn = GetOpenFileNameU(OpenFile)

'Check the return, if 0 then no files selected or user cancelled
    If lReturn = 0 Then
        BrowseForFile = ""
    Else
    'lpstrFile contains the current directory followed by list of file names
        BrowseForFile = strFile
    End If
End Function
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1 回答 1

1

您当前的问题似乎是OpenFile.lStructSize = LenB(strFile)

因为您将 strFile 设置为 257，所以它包含 574 个字节。根据结果​​，看起来 lStructSize 只有在完全适合文件的情况下才有效，因此您必须使用原始文件OpenFile.lStructSize = LenB(OpenFile)

另外，我认为 strptr 的工作方式与您使用它的方式不同，它将字符串转换为指针，反之亦然

如果这确实是问题之一，我编写了一个将指针转换为字符串的函数。不幸的是，它需要你传递长度，我在尝试从指针本身获取它时遇到了很多麻烦

Private Declare Sub CopyMemory Lib "kernel32.dll" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Function myConversion(lpstr As Long, lenStr As Integer) As String
    Dim bStr() As Byte
    On Error Resume Next

    If lenStr Then
        Dim lenBytes
        lenBytes = (lenStr) * 2
        ReDim bStr(0 To lenBytes - 1) As Byte
        Call CopyMemory(bStr(0), ByVal lpstr, lenBytes)

        Dim i
        Dim s As String
        For i = LBound(bStr) To UBound(bStr) Step 2
            s = s & Chr(bStr(i))
        Next i
    End If

    myConversion = s
End Function
于 2014-10-24T18:53:42.317 回答