Question

This problem is making me crazy.

Actually I have multiple problems.

First one:

Why on earth are is there a _Worksheet and a Worksheetinterface in the Excel interop. They both look the same, except for some attributes on the methods.

It’s confusing!

Second of all: my job today is making a VB.NET file more strict, by settings Option Strict On and Option Explicit On

While it works for most files, I’m bumping into a problem.

Here’s a little code piece:

Private _pivotTable As Excel.PivotTable

With _pivotTable
pvf = .AddDataField(pvc)
End With

PivotTable.AddDataField is defined on the MSDN page: http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.pivottable.adddatafield(office.11).aspx

When I check my local Interop dll w/ Reflector that method is NOT there.
When I run the application, and step through it, the method just works.
When I try to step INTO the method, I get an LateBound Exception.

WTF?

So the question is: why are the interfaces defined more than once (twice sometimes?).
2nd question. AddDataField trouble

Answer 1

Some of the items that are supposedly there according to msdn are not actually there within VB. I found this was the case quite a few times. Interestingly, these properties or methods are available in VBA, but not in VB.NET. To get around this, I actually created a temporary macro within the excel file I was editing, included the code to manipulate the things I couldn’t get at otherwise, and then ran it. So, it was actually VBA code written as a string in VB.NET and executed in Excel.

Here’s the code from that project. Maybe it’ll help:

'---------------------------------------------------------Nitrate Graph
        '
        '
        'Build the Nitrate graph
        Dim objExcel As New Excel.Application 'create an Excel application object
        Dim objWrkBk As Excel.Workbook 'create a workbook
        Dim objSheet As Excel.Worksheet 'create a worksheet
        Dim Range As Excel.Range 'create a range
        Dim Chart As Excel.Chart 'create a chart
        Dim chartObjects As Excel.ChartObjects = Nothing 'create a chartObjects instance
        Dim existingChartObject As Excel.ChartObject = Nothing 'create a chartObject instance

        objExcel = New Excel.Application 'start the Excel application
        objWrkBk = objExcel.Workbooks.Add 'add the workbook to this excel application
        objSheet = objWrkBk.Sheets.Add 'add the worksheet to the workbook object
        objSheet = objWrkBk.Sheets(1) 'objSheet is the first sheet in the workbook
        Chart = objExcel.Charts.Add 'add a chart to the Excel application
        'objExcel.Visible = True

        '''''''''''''''''''''''''''''''''''''''''''''
        'Create a macro to be run within the excel  '
        'application to delete a series that is     '
        'otherwise undeletable.                     '
        '''''''''''''''''''''''''''''''''''''''''''''

        Dim macro As VBIDE.VBComponent 'create a macro object
        Dim sCode As String 'create a string to hold the macro programming

retry:  'A point at which the macro creation is retried if unsuccessful

        'Add in a macro so that Excel will delete the day as the series.
        Try
            macro = objWrkBk.VBProject.VBComponents.Add(VBIDE.vbext_ComponentType.vbext_ct_StdModule) 'place the macro into the workbook
        Catch ex As Exception 'if an error occurs, catch it and do the following:
            'If the user has not enabled access to Visual Basic a Run-time error will occur.
            'Details on this error can be found here:  http://support.microsoft.com/kb/282830/en-us
            'Run-time error '6068': Programmatic Access to Visual Basic Project is not trusted 
            Dim Response As Integer
            'if the error is caught, a message box will display with the following text instructions on how to fix the problem.
            Response = MessageBox.Show("Access is denied from Microsoft Excel.  You need to do the following:" & vbCr & vbCr & _
                            "   1. Open Microsoft Office Excel 2007.  Click the Microsoft Office" & vbCr & _
                            "         button, and then click Excel Options." & vbCr & vbCr & _
                            "   2. Click the Trust Center tab, and then click Trust Center Settings." & vbCr & vbCr & _
                            "   3. Click the Macro Settings tab, click to select the Trust access to " & vbCr & _
                            "       the VBA project object model check box, and then click OK." & vbCr & vbCr & _
                            "   4. Click OK. " & vbCr & vbCr & _
                            "Restart IX Report Gen.", "Security Access Denied", MessageBoxButtons.RetryCancel, MessageBoxIcon.Exclamation)
            If Response = 4 Then 'If the user selected to retry they will be taken to the retry point above
                GoTo retry
            Else
                End 'If the user cancels the program simply ends.
            End If
        End Try

        'The macro code is put into the sCode string.
        'Line by line, the code below is described:

        'Sub Macro2()
        'ActiveSheet.ChartObjects(""Chart 1"").Activate     'Activate the chart in the sheet
        'ActiveChart.SeriesCollection(1).Select             'Select the chart's 1st data series
        'Selection.Delete                                   'Delete the chart's 1st data series
        'End Sub                                            'End the macro

        sCode = "Sub Macro2()" & vbCr & "ActiveSheet.ChartObjects(""Chart 1"").Activate" _
                & vbCr & "ActiveChart.SeriesCollection(1).Select" _
                & vbCr & "Selection.Delete" _
                & vbCr & "End Sub"
        'The sCode string is placed into the empty macro
        macro.CodeModule.AddFromString(sCode)


        'Populate the Nitrate Avegare Array
        Dim HeadingArray(1, 1) As String 'A HeadingArray is created to place headings into the Excel sheet
        HeadingArray(0, 0) = "Day" 'Heading 1 is Day
        HeadingArray(0, 1) = "Nitrate Avg" 'Heading 2 is Nitrate Avg
        Range = objSheet.Range("A1", "B1") 'Range is assigned to the cells A1 and B1
        Range.Value = HeadingArray 'The value of the range is set to the value of the HeadingArray.  A1=Day and B1=Nitrate Avg
        'Range is now assigned to the cells from A2 to the B column and 'as many rows as are in the reporting month plus 1
        'to accomodate the heading row.
        Dim BNum As Integer = ArrayRows(DailyNitrateAverageArray)
        Dim NumArray(BNum - 1, 1) As Double
        'Transfer the string array's values into a double array
        For i As Integer = 0 To BNum - 1
            NumArray(i, 0) = DailyNitrateAverageArray(i, 0)
            NumArray(i, 1) = DailyNitrateAverageArray(i, 1)
        Next

        Range = objSheet.Range("A2", "B" & BNum + 2)
        Range.Value = NumArray 'The value of Range is now assigned the values of DailyAverageArray
        Range = objSheet.Range("A1", "B" & BNum + 2) 'Range is reassigned to select the whole edited area from A1 to B#
        'This is the title later used for the chart.  An example of what the title would
        'say if it were April is, Daily Nitrate Averages for April
        Dim Title As String = "Daily Nitrate Averages for " & Month & " - Train " & GraphNumber + 1

        Chart.Location(Excel.XlChartLocation.xlLocationAsObject, objSheet.Name) 'The chart is placed into the worksheet
        ' Get the ChartObjects collection for the sheet.
        chartObjects = objSheet.ChartObjects() 'chartObjects is assigned to this sheet

        ' Get the chart to modify.  This is the first item in chartObjects
        existingChartObject = chartObjects.Item(1)

        'Custom settings are assigned to the chart using the With keyword
        With existingChartObject
            .Chart.ChartType = Excel.XlChartType.xlLine 'This is a line graph
            .Chart.SetSourceData(Range, PlotBy:=Excel.XlRowCol.xlColumns) 'we plot by the columns selected--this gives us our headings as names
            .Chart.HasLegend = True 'give the chart a legend
            .Chart.HasTitle = True 'tell the chart it has a title
            .Chart.ChartTitle.Text = Title 'give the chart its title (declared and assigned earlier)
            .Shadow = True 'Give the chart a shadow effect
            .Chart.ChartArea.Shadow = True 'Give the chart area a shadow effect
            .Chart.ChartArea.Format.Shadow.Style = MsoShadowStyle.msoShadowStyleOuterShadow 'assign an outer shadow style
            .Chart.Legend.Position = Excel.XlLegendPosition.xlLegendPositionTop 'position the legend at the top of the chart
            .Chart.ChartArea.Format.Glow.Radius = 10 'add a glow with a radius of 10
            .Chart.ChartArea.Format.Glow.Color.RGB = RGB(90, 90, 90) 'set the color of the glow to a gray color
            .Chart.ChartArea.Format.Fill.Visible = True 'make the fill on the chart visible
            'give the chart major gridlines on it's x axis
            .Chart.Axes(Excel.XlAxisGroup.xlPrimary).HasMajorGridlines = True
        End With 'Finish working with existingChartObject

        'from the perspective of the sheet, set the Width and Height to 500 X 300
        objSheet.ChartObjects(1).Width = 500
        objSheet.ChartObjects(1).Height = 300

        'Format the Chart's 2nd data series
        With existingChartObject.Chart.SeriesCollection(2)
            .Shadow = True 'give it a shadow
            .Format.Shadow.Style = MsoShadowStyle.msoShadowStyleOuterShadow 'set the shadow to be an outer shadow
            .Format.Shadow.Transparency = 0.5 'make the shadow 50% transparent
        End With 'stop working with the existingChartObject.Chart.SeriesCollection(2)

        objExcel.Run("Macro2") 'Run Macro2 to delete the unecessary series