excel vba - 高效循环2d数组

时间:2011-10-02 11:53:13

标签: excel vba scripting

我无可救药地试图找到一种更好的填充范围内容的方法。这种方式产生了正确的结果,但速度很慢。任何人都可以指出我在如何填充二维数组或加速算法方面的正确方向?我希望有人能够取得成功的代码片段,甚至只是显示更清晰方法的链接。

here is my OLD code:
----------------
    f = 1
    maxcol = 'func call to get last non blank col ref .ie could return T, R, H.etc

    For f = 1 To UBound(filenames)
        Set aDoc = LoadXmlDoc(filenames(f))
        For Each c In Worksheets("Results").Range("A1:" & maxcol & "1")
                                        c.Offset(f, 0).Value = aNode.Text
                    Next c
        Worksheets("Results").Range(maxcol & "1").Offset(f, 0).Value = filenames(f)
    Next f


UPDATED CODE:
----------

Dim aDoc As DOMDocument
Dim aNode As IXMLDOMNode
Dim numOfXpaths As Integer
Dim filenames As Variant
Dim f As Integer
Dim maxcol As String
Dim rngStart As Range
Dim nColIndex As Long
Dim lngCalc As Long
'Dim numOfFiles As Integer
Dim aXpaths As Variant
        numOfFiles = UBound(filenames)
    colToRow aXpaths, numOfXpaths
    maxcol = Number2Char(numOfXpaths)
        ReDim aValues(1 To numOfFiles, 1 To numOfXpaths + 1) As Variant
        For f = 1 To numOfFiles
            Set aDoc = LoadXmlDoc(filenames(f))
            For nColIndex = 1 To numOfXpaths
                    If aDoc.parseError Then
                        aValues(f, nColIndex) = "XML parse error:" 
                    Else
                      Set aNode = aDoc.selectSingleNode(aXpaths(nColIndex))
                      aValues(f, nColIndex) = aNode.Text
                    End If
            Next nColIndex
            aValues(f, numOfXpaths + 1) = filenames(f)
        Next f
        Worksheets("Results").Range("A1").Offset(1, 0).Resize(numOfFiles, numOfXpaths + 1).Value = aValues


    Function colToRow(ByRef aXpaths As Variant, ByRef numOfXpaths As Integer)
    Dim xpathcount As Integer
    Dim c As Integer
    'Dim aXpaths As Variant
    xpathcount = Worksheets("Xpaths").Cells(Rows.Count, "A").End(xlUp).Row - 1
    ReDim aXpaths(1 To xpathcount + 1) As Variant
    For c = 0 To xpathcount
        Worksheets("Results").Range("A1").Offset(0, c) = Worksheets("Xpaths").Range("A1").Offset(c, 0)
        Worksheets("Results").Range("A1").Offset(0, c).Columns.AutoFit
        aXpaths(c + 1) = Worksheets("Xpaths").Range("A1").Offset(c, 0)
    Next c
    Worksheets("Results").Range("A1").Offset(0, xpathcount + 1) = "Filename"
    'colToRow = xpathcount + 1
    numOfXpaths = xpathcount + 1
    End Function

Function Number2Char(ByVal c) As String
Number2Char = Split(Cells(1, c).Address, "$")(1)
End Function

3 个答案:

答案 0 :(得分:5)

为了有效地做到这一点,你应该用你想要写的数据生成一个二维数据,然后一次性写出来。

如下所示。我更喜欢基于0的数组与其他语言兼容,而您似乎使用的是基于1的数组(1 to UBound(filenames)。因此,以下未经测试的代码中可能存在逐个错误:

f = 1
maxcol = 'func call to get last non blank col ref .ie could return T, R, H.etc

' 2D array to hold results    
' 0-based indexing: UBound(filenames) rows and maxcol columns
Dim aValues(0 to UBound(filenames)-1, 0 To maxcol-1) As Variant
Dim rngStart As Range
Dim nColIndex As Long

For f = 1 To UBound(filenames)
    Set aDoc = LoadXmlDoc(filenames(f))

    aValues(f-1, 0) = filenames(f)

    For nColIndex = 1 To maxCol-1
        aValues(f-1, nColIndex) = aNode.Text
    Next nColIndex

Next f

' Copy the 2D array in one go
Worksheets("Results").Offset(1,0).Resize(UBound(filenames),maxCol).Value = aValues

答案 1 :(得分:4)

当您从XML获得结果时,您是否考虑过使用XML地图来显示信息 - 可能不适合您的情况,但值得一试。

下面的link显示了在Excel中使用XML地图的一些内容。

将XML字符串加载到定义映射中的行的语法类似于:

ActiveWorkbook.XmlMaps("MyMap").ImportXml(MyXMLDoc,True)

答案 2 :(得分:2)

您可能希望查看“在Excel VBA中使用变体数组进行大规模数据操作”中的代码,http://www.experts-exchange.com/A_2684.html(超链接中提供了更多详细信息)

请注意,由于我上面没有您的数据与本文一起使用,因此提供了一个示例解决方案(在这种情况下有效地删除了前导零)以满足您填充二维数组要求的范围。

需要注意的要点

  1. 该代码通过使用区域
  2. 处理不受欢迎的范围
  3. 当使用变体数组alwasy测试时,设置数组大小的范围大于1个单元格 - 如果不是,则无法使用变体
  4. 代码从范围读取,运行操作,然后转储回相同的范围
  5. 使用Value2的效率略高于Value
  6. 以下是代码:

    'Press Alt + F11 to open the Visual Basic Editor (VBE)
    'From the Menu, choose Insert-Module.
    'Paste the code into the right-hand code window.
    'Press Alt + F11 to close the VBE
    'In Xl2003 Goto Tools … Macro … Macros and double-click KillLeadingZeros
    
    Sub KillLeadingZeros()
        Dim rng1 As Range
        Dim rngArea As Range
        Dim lngRow As Long
        Dim lngCol As Long
        Dim lngCalc As Long
        Dim objReg As Object
        Dim X()
    
    
        On Error Resume Next
        Set rng1 = Application.InputBox("Select range for the replacement of leading zeros", "User select", Selection.Address, , , , , 8)
        If rng1 Is Nothing Then Exit Sub
        On Error GoTo 0
    
        'See Patrick Matthews excellent article on using Regular Expressions with VBA
        Set objReg = CreateObject("vbscript.regexp")
        objReg.Pattern = "^0+"
    
        'Speed up the code by turning off screenupdating and setting calculation to manual
        'Disable any code events that may occur when writing to cells
        With Application
            lngCalc = .Calculation
            .ScreenUpdating = False
            .Calculation = xlCalculationManual
            .EnableEvents = False
        End With
    
        'Test each area in the user selected range
    
        'Non contiguous range areas are common when using SpecialCells to define specific cell types to work on
        For Each rngArea In rng1.Areas
            'The most common outcome is used for the True outcome to optimise code speed
            If rngArea.Cells.Count > 1 Then
               'If there is more than once cell then set the variant array to the dimensions of the range area
               'Using Value2 provides a useful speed improvement over Value. On my testing it was 2% on blank cells, up to 10% on non-blanks    
                X = rngArea.Value2
                For lngRow = 1 To rngArea.Rows.Count
                    For lngCol = 1 To rngArea.Columns.Count
                        'replace the leading zeroes
                        X(lngRow, lngCol) = objReg.Replace(X(lngRow, lngCol), vbNullString)
                    Next lngCol
                Next lngRow
                'Dump the updated array sans leading zeroes back over the initial range
                rngArea.Value2 = X
            Else
                'caters for a single cell range area. No variant array required
                rngArea.Value = objReg.Replace(rngArea.Value, vbNullString)
            End If
        Next rngArea
    
        'cleanup the Application settings
        With Application
            .ScreenUpdating = True
            .Calculation = lngCalc
            .EnableEvents = True
        End With
    
        Set objReg = Nothing
        End Sub