VB下幾個非常有用的函數

'————————（1）————————————
'獲得指定ini檔案中某個節下面的所有索引值 TrueZq,,需要下面的API聲明
'Private Declare Function GetPrivateProfileSection Lib "kernel32" Alias "GetPrivateProfileSectionA" (ByVal lpAppName As String, ByVal lpReturnedString As String, ByVal nSize As Long, ByVal lpFileName As String) As Long
'返回一個字串數組
'調用舉例：
'Dim arrClass() As String
'arrClass = GetInfoSection("class", "d:/type.ini")
 
Public Function GetInfoSection(strSection As String, strIniFile As String) As String()
    Dim strReturn As String * 32767
    Dim strTmp As String
    Dim nStart As Integer, nEnd As Integer, i As Integer
    Dim sArray() As String
   
    Call GetPrivateProfileSection(strSection, strReturn, Len(strReturn), strIniFile)
   
    strTmp = strReturn
    i = 1
    Do While strTmp <> ""
        nStart = nEnd + 1
        nEnd = InStr(nStart, strReturn, vbNullChar)
        strTmp = Mid$(strReturn, nStart, nEnd - nStart)
        If Len(strTmp) > 0 Then
            ReDim Preserve sArray(1 To i)
            sArray(i) = strTmp
            i = i + 1
        End If
       
    Loop
    GetInfoSection = sArray
End Function

'————————（2）————————————
'作用：去掉字串中的首尾空格、所有無效字元
'測試案例
'Dim strRes As String
'Dim strSour As String
'
'strSour = " " & vbNullChar & vbNullChar & " ab cd" & vbNullChar
'strRes = zqTrim(strSour)
'MsgBox " 長度=" & Len(strSour) & "值=111" & strRes & "222"
Public Function zqTrim(ByVal strSour As String) As String
    Dim strTmp As String
    Dim nLen As Integer
    Dim i As Integer, j As Integer
    Dim strNow As String, strValid() As String, strNew As String
    'strNow 當前字元
    'strValid 有效字元
    'strNew 最後產生的新字元
   
    strTmp = Trim$(strSour)
    nLen = Len(strTmp)
    If nLen < 1 Then
        zqTrim = ""
        Exit Function
    End If
    j = 0
    For i = 1 To nLen
        strNow = Mid(strTmp, i, 1) '每次讀取一個字元
        'MsgBox Asc(strNow)
        If strNow <> vbNullChar And Asc(strNow) <> 9 Then '如果有效，則存入有效數組
            ReDim Preserve strValid(j)
            strValid(j) = strNow
            j = j + 1
        End If
   
    Next i
   
    strNew = Join(strValid, "") '將所有有效字元串連起來
    zqTrim = Trim$(strNew) '去掉字串中的首尾空格
End Function

'————————（3）————————————
'檢查檔案是否存在,存在返回 TRUE,否則返回FALSE
Public Function CheckFileExist(strFile As String) As Boolean   
    If Dir(strFile, vbDirectory) <> "" Then
        CheckFileExist = True
    Else
        CheckFileExist = False
    End If
End Function

'————————（4）————————————
'獲得指定ini檔案中某個節下面某個子鍵的索引值,需要下面的API聲明
'Public Declare Function GetPrivateProfileString Lib "kernel32" Alias _
'    "GetPrivateProfileStringA" (ByVal lpApplicationName As String, _
'    ByVal lpKeyName As Any, ByVal lpDefault As String, ByVal lpReturnedString _
'    As String, ByVal nSize As Long, ByVal lpFileName As String) As Long
'返回一個字串
'調用舉例：
'Dim strRun As String
'strRun = GetiniValue("Windows","Run", "C:/Windows/Win.ini")

Public Function GetiniValue(ByVal lpKeyName As String, ByVal strName As String, ByVal strIniFile As String) As String
    Dim strTmp As String * 255
   
    Call GetPrivateProfileString(lpKeyName, strName, "", _
            strTmp, Len(strTmp), strIniFile)
    GetiniValue = Left$(strTmp, InStr(strTmp, vbNullChar) - 1)
   
End Function

'————————（5）————————————
'獲得Windows目錄 ,需要下面的API聲明
'Private Declare Function GetWindowsDirectory Lib "kernel32" Alias "GetWindowsDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long
'返回一個字串，如“C:/Windows”、“C:/Winnt”
'調用舉例：
'Dim strWindir As String
'strWindir = GetWinDir()
Private Function GetWinDir()
    Dim windir As String * 100
    Call GetWindowsDirectory(windir, 100)
    GetWinDir = Left$(windir, InStr(windir, vbNullChar) - 1)
   
End Function

'————————（6）————————————
'獲得Windows系統目錄,需要下面的API聲明
'Private Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long
'返回一個字串，如“C:/Windows/System”、“C:/Winnt/System32”
'調用舉例：
'Dim strSysDir As String
'strSysDir = GetSystemDir()
Private Function GetSystemDir()
    Dim strSysDir As String * 100
    Call GetSystemDirectory(strSysDir, 100)
    GetSystemDir = Left$(strSysDir, InStr(strSysDir, vbNullChar) - 1)   
End Function