c语言sscanf函数的用法是什么
316
2023-05-26
VB.NET经过长时间的发展,很多用户都很了解VB.NET了,这里我来拓展介绍一下VB.NET API函数的运用,让大家更好的深入了解。
以下代码演示了如何用Windows VB.NET 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
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APIPrivate 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APIPrivate 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 LongPrivate 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 pathpath = 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 DirCountDirCount = DirCount + 1 nDirnDir = 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 FindFilesAPIFindFilesAPI = FindFilesAPI + (WFD.nFileSizeHigh * MAXDWORD) + WFD.nFileSizeLow FileCountFileCount = 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 FindFilesAPIFindFilesAPI = 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 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 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88.89.90.91.92.93.94.95.96.97.98.99.100.101.102.103.104.105.106.107.108.109.110.111.112.113.114.115.116.117.118.119.120.121.122.123.124.125.126.127.128.129.130.131.132.133.134.135.136.137.138.139.140.141.142.143.144.145.146.147.148.149.150.151.152.153.154.155.156.157.158.159.160.161.162.163.164.165.166.167.168.169.170.171.172.173.174.175.176.177.178.179.以上就是VB.NET API函数的实例,希望对大家有帮助。
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