确实,VBA 有一个限制(我认为是错误或设计缺陷),其中文件系统对象的 Files 集合不能通过项目索引号访问,只能通过每个项目的文件路径字符串值访问。此处发布的原始问题是关于仅访问 Files 集合中的第一项,但它涉及一个一般问题,对此有两种合理的解决方法:创建和使用 File 对象元集合或 File 对象数组以提供索引访问 Files 集合。这是一个演示程序:
Sub DemoIndexedFileAccess()
'
'Demonstrates use of both a File object meta-collection and a File object array to provide indexed access
'to a Folder object's Files collection.
'
'Note that, in both examples, the File objects being accessed refer to the same File objects as those in
'the Folder object's Files collection. (i.e. if one of the physical files gets renamed after the creation
'of the Folder object's Files collection, all three sets of File objects will refer to the same, renamed
'file.)
'
'IMPORTANT: This technique requires a reference to "Microsoft Scripting Runtime" be set.
'
'**********************************************************************************************************
'File-selector dialog contsants for msoFileDialogFilePicker and msoFileDialogOpen:
Const fsdCancel As Integer = 0 'File dialog Cancel button
Const fsdAction As Integer = -1 'File dialog Action button, and its aliases...
Const fsdOpen As Integer = fsdAction
Const fsdSaveAs As Integer = fsdAction
Const fsdOK As Integer = fsdAction
Dim FD As FileDialog
Dim File As Scripting.File
Dim FileArr() As Scripting.File
Dim FileColl As New Collection
Dim Folder As Scripting.Folder
Dim FSO As Scripting.FileSystemObject
Dim Idx As Integer
'Get a folder specification from which files are to be processed
Set FD = Application.FileDialog(msoFileDialogFolderPicker) 'Create the FolderPicker dialog object
With FD
.Title = "Select Folder Of Files To Be Processed"
.InitialFileName = CurDir
If .Show <> fsdOK Then Exit Sub
End With
'Use the folder specification to create a Folder object.
Set FSO = New Scripting.FileSystemObject
Set Folder = FSO.GetFolder(FD.SelectedItems(1))
'A Folder object's Files collection can't be accessed by item-index number (only by each item's file-path
'string value), so either...
'1. Create a generic "meta-collection" that replicates the Files collection's File objects, which allows
' access by collection-item index:
For Each File In Folder.Files
FileColl.Add File
Next File
'"Process" the files in (collection) index order
For Idx = 1 To FileColl.Count
Debug.Print "Meta-Collection: " & FileColl(Idx).Name
Next Idx
'2. Or, create an array of File objects that refer to the Files collection's File objects, which allows
' access by array index:
ReDim FileArr(1 To Folder.Files.Count)
Idx = 1
For Each File In Folder.Files
Set FileArr(Idx) = File
Idx = Idx + 1
Next File
'"Process" the files in (array) index order
For Idx = LBound(FileArr) To UBound(FileArr)
Debug.Print "File Object Array: " & FileArr(Idx).Name
Next Idx
End Sub