通过VBA Excel分页符

Question

作为报告生成器的大修的一部分,我看到了我认为效率低下的代码.这部分代码在生成主报表后运行,以便在逻辑位置设置分页符.标准是这样的:

• 每个站点都在新页面上启动.
• 群组不允许跨页面.

代码遵循以上格式:2个循环执行这些作业.

这是原始代码(抱歉长度):

Public Sub PageBreak(ByRef wstWorksheet As Excel.Worksheet, ByVal pctProgress As ProgressCtl.ProgressControl)
Dim breaksMoved As Integer
Dim p As HPageBreak
Dim i As Integer

'Used as a control value
breaksMoved = 1

' Marks that no rows/columns are to be repeated on each page
wstWorksheet.Activate
wstWorksheet.PageSetup.PrintTitleRows = ""
wstWorksheet.PageSetup.PrintTitleColumns = ""

'If this isn't performed beforehand, then the HPageBreaks object isn't available
Range("A3").Select
ActiveWindow.View = xlPageBreakPreview

'Defaults the print area to be the entire sheet
wstWorksheet.DisplayPageBreaks = False
wstWorksheet.PageSetup.PrintArea = ""

Range("$B$4").Select

' add breaks after each site
Do While ActiveCell.Row <= wstWorksheet.UsedRange.Rows.Count
    If ActiveCell.FormulaR1C1 = "Site ID" Then
        ActiveCell.PageBreak = xlPageBreakManual
    End If
    ActiveCell.Offset(1, 0).Activate
    pctProgress.ProgressText = "Row " & CStr(ActiveCell.Row) & " of " & CStr(wstWorksheet.UsedRange.Rows.Count)
Loop

Dim passes As Long
Do While breaksMoved = 1
    passes = passes + 1
    breaksMoved = 0
    For i = 1 To wstWorksheet.HPageBreaks.Count - 1
            Set p = wstWorksheet.HPageBreaks.Item(i)
            'Selects the first page break
            Range(p.Location.Address).Select
            'Sets the ActiveCell to 1 row above the page break
            ActiveCell.Offset(-1, 0).Activate

            'Move the intended break point up to the first blank section
            Do While Not ActiveCell.FormulaR1C1 = ""
                ActiveCell.Offset(-1, 0).Activate
                breaksMoved = 1
            Loop

            'Add the page break
            If ActiveCell.FormulaR1C1 <> "Site ID" Then
                ActiveCell.Offset(1, 0).Activate
                wstWorksheet.HPageBreaks.Add ActiveCell
            End If

            pctProgress.ProgressText = "Set break point " & CStr(passes) & "." & CStr(i)

    Next

Loop

'Reset the view to normal
wstWorksheet.DisplayPageBreaks = True
ActiveWindow.View = xlNormalView
Range("A3").Select
End Sub

看到改进的空间我着手修改这个.作为新要求之一,人们想要报告是在打印之前手动删除页面.所以我在另一个页面上添加了复选框并复制了选中的项目.为了方便我使用命名范围.我使用这些命名范围来满足第一个要求:

' add breaks after each site   
For Each RangeName In ActiveWorkbook.Names
    If Mid(RangeName.Name, 1, 1) = "P" Then
        Range(RangeName).Activate
        ActiveCell.Offset(Range(RangeName).Rows.Count - 1, 0).Select
        ActiveCell.PageBreak = xlPageBreakManual
    End If
Next RangeName

所有范围都以P_为前缀(对于父级).使用蹩脚的Now()风格的粗略时间,这在我的短4站点报告和更具挑战性的15站点报告上慢了1秒.它们分别有606和1600行.

1秒并不是那么糟糕.让我们看看下一个标准.每个逻辑组都由一个空行拆分,因此最简单的方法是找到下一个分页符,然后返回,直到找到下一个空白行并插入新的分隔符.冲洗并重复.

那么为什么原版会经历多次？我们也可以改进它(循环外的锅炉板是相同的).

Dim i As Long
Dim oPageBreak As HPageBreak
Do While i < shtDeliveryVariance.HPageBreaks.Count - 1
    i = i + 1
    pctProgress.ProgressText = "Setting Page Break " & CStr(i) & " of " & CStr(shtDeliveryVariance.HPageBreaks.Count)

    Set oPageBreak = shtDeliveryVariance.HPageBreaks.Item(i)

    ' select the page break
    Range(oPageBreak.Location.Address).Select
    ActiveCell.Offset(-1, 0).Activate

    ' move up to a free row
    Do While Not ActiveCell.FormulaR1C1 = ""
        ActiveCell.Offset(-1, 0).Activate
    Loop

    'Add the page break
    If ActiveCell.FormulaR1C1 <> "Site ID" Then
        ActiveCell.Offset(1, 0).Activate
        shtDeliveryVariance.HPageBreaks.Add ActiveCell
    End If

Loop

一次通过也更优雅.但它快多少？在较小的测试中,与原始的45秒相比需要54秒,而在较大的测试中,我的代码在153到130秒时再次变慢.这也是3次运行的平均值.

所以我的问题是:为什么我的新代码比原版慢得多,尽管我看起来更快,我该怎么做才能加快代码的缓慢？

注意:Screen.Updating等已经关闭,计算等.

Answer 1

我看到代码中的几个地方有改进的余地:

1. 不要访问缓慢执行的属性,比如usedrange.rows.count多次(特别是在循环内),除非您认为它们可能有更改.而是将它们存储在变量中.
2. 如果可以避免文本比较,请不要进行文本比较(例如:.Value =""),而是使用LenB函数检查空白,它会执行得更快,因为它只是读取字符串标题的长度而不是启动到逐字节字符串比较.(你可能会喜欢这个阅读.)
3. 不要使用"激活"或"选择"来移动ActiveCell,只需直接访问该范围.
4. 循环时,构造循环必须执行尽可能少的测试.如果循环必须始终执行一次,那么您需要一个测试后循环.
5. 确保锁定Excel界面,因为运行事件和屏幕更新等可能会使代码速度降低.(特别是活动.)
6. 最后,我注意到您正在对"站点ID"的情况做出假设,除非没有其他可能的方法,否则最好进行不区分大小写的比较.如果您知道它将以某种方式进行Cased,您当然可以删除我添加的对LCase $的调用.

我重构了原始代码,为您提供了一些这些想法的示例.在不知道您的数据布局的情况下,很难确定此代码是否100%有效,因此我会仔细检查它是否存在逻辑错误.但它应该让你开始.

Public Sub PageBreak(ByRef wstWorksheet As Excel.Worksheet, ByVal pctProgress As ProgressCtl.ProgressContro)
        Const lngColSiteID_c As Long = 2&
        Const lngColSiteIDSecondary_c As Long = 1&
        Const lngOffset_c As Long = 1&
        Dim breaksMoved As Boolean
        Dim lngRowBtm As Long
        Dim lngRow As Long
        Dim p As Excel.HPageBreak
        Dim i As Integer
        Dim passes As Long
        Dim lngHBrksUprBnd As Long
        LockInterface True
        ' Marks that no rows/columns are to be repeated on each page
        wstWorksheet.Activate
        wstWorksheet.PageSetup.PrintTitleRows = vbNullString
        wstWorksheet.PageSetup.PrintTitleColumns = vbNullString


        'If this isn't performed beforehand, then the HPageBreaks object isn't available
        '***Not true:)***

        'ActiveWindow.View = xlPageBreakPreview

        'Defaults the print area to be the entire sheet
        wstWorksheet.DisplayPageBreaks = False
        wstWorksheet.PageSetup.PrintArea = vbNullString

        ' add breaks after each site
        lngRowBtm = wstWorksheet.UsedRange.Rows.Count
        For lngRow = 4& To lngRowBtm
            'LCase is to make comparison case insensitive.
            If LCase$(wstWorksheet.Cells(lngRow, lngColSiteID_c).value) = "site id" Then
                wstWorksheet.Cells(lngRow, lngColSiteID_c).PageBreak = xlPageBreakManual
            End If
            pctProgress.ProgressText = ("Row " & CStr(lngRow)) & (" of " & CStr(lngRowBtm))
        Next

        lngHBrksUprBnd = wstWorksheet.HPageBreaks.Count - lngOffset_c
        Do  'Using post test.
            passes = passes + lngOffset_c
            breaksMoved = False
            For i = 1 To lngHBrksUprBnd
                Set p = wstWorksheet.HPageBreaks.Item(i)
                'Move the intended break point up to the first blank section
                lngRow = p.Location.Row - lngOffset_c
                For lngRow = p.Location.Row - lngOffset_c To 1& Step -1&
                    'Checking the LenB is faster than a string check.
                    If LenB(wstWorksheet.Cells(lngRow, lngColSiteIDSecondary_c).Formula) = 0& Then
                        lngRow = lngRow - lngOffset_c
                        If LCase$(wstWorksheet.Cells(lngRow, lngColSiteIDSecondary_c).value) = "site id" Then
                            breaksMoved = True
                            wstWorksheet.HPageBreaks.Add wstWorksheet.Cells(lngRow, lngColSiteIDSecondary_c)
                        End If
                        Exit For
                    End If
                Next
                pctProgress.ProgressText = "Set break point " & (CStr(passes) & "." & CStr(i))
            Next
        Loop While breaksMoved
        LockInterface False
    End Sub

    Private Sub LockInterface(ByVal interfaceOff As Boolean)
        With Excel.Application
            If interfaceOff Then
                .ScreenUpdating = False
                .EnableEvents = False
                .Cursor = xlWait
                .StatusBar = "Working..."
            Else
                .ScreenUpdating = True
                .EnableEvents = True
                .Cursor = xlDefault
                .StatusBar = False
            End If
        End With
    End Sub