用API函数遍历指定驱动器、目录的文件

答案：
用API函数遍历指定驱动器、目录的文件
    作者：土人
以下代码演示了如何用Windows API函数遍历指定驱动器、目录的所有文件。其思路是：调出浏览文件夹窗口让用户指定所要搜索的起始路径，然后用查找文件的API函数遍历该目录下及其包含的子目录下的所有文件。本例需要：一个按钮，一个TextBox和一个ListBox，其中，TextBox应设置为多行。
   核心代码参照API-Guide的两个例子程序，特此声明。
  
  Option Explicit
   
  '查找第一个文件的API
  Private Declare Function FindFirstFile Lib "kernel32" Alias "FindFirstFileA"    (ByVal lpFileName As String, lpFindFileData As WIN32_FIND_DATA) As Long
   '查找下一个文件的API
  Private Declare Function FindNextFile Lib "kernel32" Alias "FindNextFileA"    (ByVal hFindFile As Long, lpFindFileData As WIN32_FIND_DATA) As Long
   '获取文件属性的API
  Private Declare Function GetFileAttributes Lib "kernel32" Alias "GetFileAttributesA"    (ByVal lpFileName As String) As Long
   '关闭查找文件的API
  Private Declare Function FindClose Lib "kernel32" (ByVal hFindFile As Long) As Long
   '以下为调用浏览文件夹窗口的API
  Private Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal hMem As Long)
   Private Declare Function lstrcat Lib "kernel32" Alias "lstrcatA" (ByVal lpString1 As    String, ByVal lpString2 As String) As Long
   Private Declare Function SHBrowseForFolder Lib "shell32" (lpbi As BrowseInfo) As Long
   Private Declare Function SHGetPathFromIDList Lib "shell32" (ByVal pidList As Long,    ByVal lpBuffer As String) As Long
   
  '常量
  Const MAX_PATH = 260
   Const MAXDWORD = &HFFFF
   Const INVALID_HANDLE_VALUE = -1
   Const FILE_ATTRIBUTE_ARCHIVE = &H20
   Const FILE_ATTRIBUTE_DIRECTORY = &H10
   Const FILE_ATTRIBUTE_HIDDEN = &H2
   Const FILE_ATTRIBUTE_NORMAL = &H80
   Const FILE_ATTRIBUTE_READONLY = &H1
   Const FILE_ATTRIBUTE_SYSTEM = &H4
   Const FILE_ATTRIBUTE_TEMPORARY = &H100
   Const BIF_RETURNONLYFSDIRS = 1
   Private Type FILETIME
     dwLowDateTime As Long
     dwHighDateTime As Long
   End Type
   
  '定义类(用于查找文件)
  Private Type WIN32_FIND_DATA
     dwFileAttributes As Long
     ftCreationTime As FILETIME
     ftLastAccessTime As FILETIME
     ftLastWriteTime As FILETIME
     nFileSizeHigh As Long
     nFileSizeLow As Long
     dwReserved0 As Long
     dwReserved1 As Long
     cFileName As String * MAX_PATH
     cAlternate As String * 14
   End Type
   
  '定义类(用于浏览文件夹窗口)
  Private Type BrowseInfo
     hWndOwner As Long
     pIDLRoot As Long
     pszDisplayName As Long
     lpszTitle As Long
     ulFlags As Long
     lpfnCallback As Long
     lParam As Long
     iImage As Long
   End Type
   
  '自定义函数
  Function StripNulls(OriginalStr As String) As String
     If (InStr(OriginalStr, Chr(0)) > 0) Then
         OriginalStr = Left(OriginalStr, InStr(OriginalStr, Chr(0)) - 1)
     End If
     StripNulls = OriginalStr
   End Function
   
  '自定义函数
  Function FindFilesAPI(path As String, SearchStr As String, FileCount As Integer, _
     DirCount As Integer)
     Dim FileName As String ' 文件名
     Dim DirName As String ' 子目录名
     Dim dirNames() As String ' 目录数组
     Dim nDir As Integer ' 当前路径的目录数
     Dim i As Integer ' 循环计数器变量
     Dim hSearch As Long ' 搜索句柄变量
     Dim WFD As WIN32_FIND_DATA
     Dim Cont As Integer
     If Right(path, 1) <> "\" Then path = path & "\"
     '搜索子目录
    nDir = 0
     ReDim dirNames(nDir)
     Cont = True
     hSearch = FindFirstFile(path & "*", WFD)
     If hSearch <> INVALID_HANDLE_VALUE Then
         Do While Cont
         DirName = StripNulls(WFD.cFileName)
         If (DirName <> ".") And (DirName <> "..") Then
             If GetFileAttributes(path & DirName) And FILE_ATTRIBUTE_DIRECTORY Then
                 dirNames(nDir) = DirName
                 DirCount = DirCount + 1
                 nDir = nDir + 1
                 ReDim Preserve dirNames(nDir)
             End If
         End If
         Cont = FindNextFile(hSearch, WFD) '获取下一个子目录
         Loop
        Cont = FindClose(hSearch)
     End If
     ' 遍历目录并累计文件总数
     hSearch = FindFirstFile(path & SearchStr, WFD)
     Cont = True
     If hSearch <> INVALID_HANDLE_VALUE Then
         While Cont
             FileName = StripNulls(WFD.cFileName)
             If (FileName <> ".") And (FileName <> "..") Then
                 FindFilesAPI = FindFilesAPI + (WFD.nFileSizeHigh * MAXDWORD) + WFD.nFileSizeLow
                 FileCount = FileCount + 1
                 List1.AddItem path & FileName
             End If
             Cont = FindNextFile(hSearch, WFD) ' 获取下一个文件
         Wend
        Cont = FindClose(hSearch)
     End If
     '如果子目录存在则遍历之
    If nDir > 0 Then
         For i = 0 To nDir - 1
             FindFilesAPI = FindFilesAPI + FindFilesAPI(path & dirNames(i) & "\", _
                 SearchStr, FileCount, DirCount)
         Next i
     End If
   End Function
   
  '查找按钮代码
  Sub Command1_Click()
     Dim SearchPath As String, FindStr As String
     Dim FileSize As Long
     Dim NumFiles As Integer, NumDirs As Integer
     Dim iNull As Integer, lpIDList As Long, lResult As Long
     Dim sPath As String, udtBI As BrowseInfo
     With udtBI
         '设置浏览窗口
        .hWndOwner = Me.hWnd
         '返回选中的目录
        .ulFlags = BIF_RETURNONLYFSDIRS
     End With
   
    '调出浏览窗口
    lpIDList = SHBrowseForFolder(udtBI)
     If lpIDList Then
         sPath = String$(MAX_PATH, 0)
         '获取路径
        SHGetPathFromIDList lpIDList, sPath
         '释放内存
        CoTaskMemFree lpIDList
         iNull = InStr(sPath, vbNullChar)
         If iNull Then
             sPath = Left$(sPath, iNull - 1)
         End If
     End If
   
    Screen.MousePointer = vbHourglass
     List1.Clear
    SearchPath = sPath  '选中的目录为搜索的起始路径
     FindStr = "*.*"  '搜索所有类型的文件(此处可另作定义)
     FileSize = FindFilesAPI(SearchPath, FindStr, NumFiles, NumDirs)
     Text1.Text = "查找到的文件数：" & NumFiles & vbCrLf & "查找的目录数：" & _
         NumDirs + 1 & vbCrLf & "文件大小总共为：" & vbCrLf & _
         Format(FileSize, "#,###,###,##0") & "字节"
     Screen.MousePointer = vbDefault
   End Sub   

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