Excel VBA模块中的内存泄漏

时间:2018-03-14 19:02:47

标签: excel-vba memory-leaks vba excel

我需要一个能够扫描我的数组并在ColumnWidths中为我的ListBox返回UserForm的函数。过了一会儿,我找到了This StackOverflow topic。我修复并使用了代码时出现了一些错误。工作得很好!

但是我注意到当我打开和关闭UserForm几次(10-20x)时,开口越来越长。而Excel的内存使用量也越来越大。每次运行大约1MB。

所以我认为这是这个模块。有没有人能够看到那里是否有内存泄漏?

我使用的代码是:

Option Explicit

' ==========================================================================
' SOURCE for this module, slightly modified code from TravelinGuy
' https://stackoverflow.com/questions/5012465/vb-macro-string-width-in-pixel
'
' Adds functions:
'     GetStringPixelHeight(text:Str, fontName:Str, fontSize:Single, _
'                          [isBold:Bool=False], [isItalics:Bool=False])
'     GetStringPixelWidth(text:Str, fontName:Str, fontSize:Single, _
'                         [isBold:Bool=False], [isItalics:Bool=False]))
'     GetLabelPixelHeight(label:Str)
'     GetLabelPixelWidth(label:Str)
' ==========================================================================

'API Declares

Private Declare Function CreateDC Lib "gdi32.dll" Alias "CreateDCA" (ByVal lpDriverName As String, ByVal lpDeviceName As String, ByVal lpOutput As String, lpInitData As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32.dll" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function CreateFontIndirect Lib "gdi32.dll" Alias "CreateFontIndirectA" (lpLogFont As LOGFONT) As Long
Private Declare Function SelectObject Lib "gdi32.dll" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteObject Lib "gdi32.dll" (ByVal hObject As Long) As Long
Private Declare Function GetTextExtentPoint32 Lib "gdi32.dll" Alias "GetTextExtentPoint32A" (ByVal hdc As Long, ByVal lpsz As String, ByVal cbString As Long, lpSize As FNTSIZE) As Long
Private Declare Function MulDiv Lib "kernel32.dll" (ByVal nNumber As Long, ByVal nNumerator As Long, ByVal nDenominator As Long) As Long
Private Declare Function GetDC Lib "user32.dll" (ByVal hwnd As Long) As Long
Private Declare Function GetDeviceCaps Lib "gdi32.dll" (ByVal hdc As Long, ByVal nIndex As Long) As Long
Private Declare Function DeleteDC Lib "gdi32.dll" (ByVal hdc As Long) As Long

Private Const LOGPIXELSY As Long = 90

Private Type LOGFONT
    lfHeight As Long
    lfWidth As Long
    lfEscapement As Long
    lfOrientation As Long
    lfWeight As Long
    lfItalic As Byte
    lfUnderline As Byte
    lfStrikeOut As Byte
    lfCharSet As Byte
    lfOutPrecision As Byte
    lfClipPrecision As Byte
    lfQuality As Byte
    lfPitchAndFamily As Byte
    lfFaceName As String * 32
End Type

Private Type FNTSIZE
    cx As Long
    cy As Long
End Type


Public Function GetLabelPixelWidth(label As String) As Integer

    Dim font As New StdFont
    Dim sz As FNTSIZE
    font.Name = "Arial Narrow"
    font.size = 9.5

    sz = GetLabelSize(label, font)
    GetLabelPixelWidth = sz.cx

End Function


Public Function GetStringPixelHeight(text As String, fontName As String, fontSize As Single, Optional isBold As Boolean = False, Optional isItalics As Boolean = False) As Integer

    Dim font As New StdFont
    Dim sz As FNTSIZE
    font.Name = fontName
    font.size = fontSize
    font.Bold = isBold
    font.Italic = isItalics

    sz = GetLabelSize(text, font)
    GetStringPixelHeight = sz.cy

End Function


Public Function GetStringPixelWidth(text As String, fontName As String, fontSize As Single, Optional isBold As Boolean = False, Optional isItalics As Boolean = False) As Integer

    Dim font As New StdFont
    Dim sz As FNTSIZE
    font.Name = fontName
    font.size = fontSize
    font.Bold = isBold
    font.Italic = isItalics

    sz = GetLabelSize(text, font)
    GetStringPixelWidth = sz.cx

End Function


Private Function GetLabelSize(text As String, font As StdFont) As FNTSIZE
    Dim tempDC As Long
    Dim tempBMP As Long
    Dim f As Long
    Dim lf As LOGFONT
    Dim textSize As FNTSIZE

    ' Create a device context and a bitmap that can be used to store a
    ' temporary font object
    tempDC = CreateDC("DISPLAY", vbNullString, vbNullString, ByVal 0)
    tempBMP = CreateCompatibleBitmap(tempDC, 1, 1)

    ' Assign the bitmap to the device context
    DeleteObject SelectObject(tempDC, tempBMP)

    ' Set up the LOGFONT structure and create the font
    lf.lfFaceName = font.Name & Chr$(0)
    lf.lfHeight = -MulDiv(font.size, GetDeviceCaps(GetDC(0), 90), 72) 'LOGPIXELSY
    lf.lfItalic = font.Italic
    lf.lfStrikeOut = font.Strikethrough
    lf.lfUnderline = font.Underline
    If font.Bold Then lf.lfWeight = 800 Else lf.lfWeight = 400
    f = CreateFontIndirect(lf)

    ' Assign the font to the device context
    DeleteObject SelectObject(tempDC, f)

    ' Measure the text, and return it into the textSize SIZE structure
    GetTextExtentPoint32 tempDC, text, Len(text), textSize

    ' Clean up (very important to avoid memory leaks!)
    DeleteObject f
    DeleteObject tempBMP
    DeleteDC tempDC
    ' Return the measurements
    GetLabelSize = textSize

End Function

用于构造ListBox.ColumnWidths字符串的函数是:

' Return string with column widths from entered myarray values for lstbox.ColumnWidths
' Example: "80;40;49;65;30;21;19;65"
'---------------------------------------------------------------------------------------
Public Function getLstColumnWidths(ByVal myarray As Variant, _
                                   Optional multiplier As Single = 1) As String

    Dim currentVal As Long
    Dim longestVal As Long

    ' Get Column Widths from the largest string in column
    getLstColumnWidths = ""

    Dim i As Long
    Dim j As Long
    For i = LBound(myarray, 1) To UBound(myarray, 1)
        longestVal = 0
        For j = LBound(myarray, 2) To UBound(myarray, 2)
            Dim strText As String
            strText = myarray(i, j)
            ' MEMORY LEAKS?
            currentVal = GetStringPixelWidth(strText, "Tahoma", 8  ' <-- USED HERE
            longestVal = IIf(currentVal > longestVal, currentVal, longestVal)
        Next j
        getLstColumnWidths = getLstColumnWidths & _
            CStr(Round(longestVal * multiplier, 1)) & ";"
    Next i
    getLstColumnWidths = Left(getLstColumnWidths, Len(getLstColumnWidths) - 1)
End Function

0 个答案:

没有答案