merge cells with same values in microsoft office interop excel

Question

i created a report which exports to excel. it exports just fine. what i want to do now is merge the consecutive cells in a column which have the same values. how do i do this? please help me.

this is code that generates the excel body:

Protected Sub generateExcelBody(ByVal xcelworksheet As Microsoft.Office.Interop.Excel.Worksheet, ByVal recarray As Array, ByVal numofrecords As Integer)
    Dim chartrange As Microsoft.Office.Interop.Excel.Range
    chartrange = Nothing
    chartrange = xcelworksheet.Range("B5", "F5")
    chartrange.MergeCells = True
    chartrange.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignLeft
    chartrange.VerticalAlignment = Microsoft.Office.Interop.Excel.XlVAlign.xlVAlignCenter

    chartrange = Nothing
    chartrange = xcelworksheet.Range("A8", System.Reflection.Missing.Value)
    chartrange.FormulaR1C1 = "Record Series : " & hiddenrs.Value
    chartrange = Nothing
    chartrange = xcelworksheet.Range("A9", System.Reflection.Missing.Value)
    chartrange.FormulaR1C1 = "Department : " & hiddendept.Value
    chartrange = Nothing
    chartrange = xcelworksheet.Range("A10", System.Reflection.Missing.Value)
    chartrange.FormulaR1C1 = "Number of Records : " & numofrecords
    chartrange = Nothing
    chartrange = xcelworksheet.Range("A14", "F14")
    chartrange.Resize(numofrecords, 6).Value2 = recarray
    chartrange.Resize(numofrecords, 6).Borders(Microsoft.Office.Interop.Excel.XlBordersIndex.xlEdgeLeft).Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlMedium
    chartrange.Resize(numofrecords, 6).Borders(Microsoft.Office.Interop.Excel.XlBordersIndex.xlEdgeRight).Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlMedium
    chartrange.Resize(numofrecords, 6).Borders(Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideHorizontal).Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlThin
    chartrange.Resize(numofrecords, 6).Borders(Microsoft.Office.Interop.Excel.XlBordersIndex.xlInsideVertical).Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlThin
    chartrange.Resize(numofrecords, 6).Borders(Microsoft.Office.Interop.Excel.XlBordersIndex.xlEdgeBottom).Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlMedium
    chartrange.Resize(numofrecords, 6).WrapText = True
    chartrange.Resize(numofrecords, 6).EntireRow.AutoFit()
    chartrange.Resize(numofrecords, 6).Font.Size = 10
    chartrange.Resize(numofrecords, 6).HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignCenter
    chartrange.Resize(numofrecords, 6).VerticalAlignment = Microsoft.Office.Interop.Excel.XlVAlign.xlVAlignCenter
End Sub

Answer 1

I just received a notification that this question got 1000+ views so I thought I'd post what I did a year ago in solution to this problem. I hope you guys find it useful.

Public Sub mergeRows(ByVal grid As GridView)
    For rowIndex As Integer = (grid.Rows.Count - 2) To 0 Step -1
        Dim currRow As GridViewRow = grid.Rows(rowIndex)
        Dim prevRow As GridViewRow = grid.Rows(rowIndex + 1)

        For i As Integer = 0 To (currRow.Cells.Count - 1)
            If currRow.Cells(0).Text = prevRow.Cells(i).Text Then
                currRow.Cells(0).RowSpan = IIf(prevRow.Cells(0).RowSpan < 2, 2, prevRow.Cells(0).RowSpan + 1)
                prevRow.Cells(0).Visible = False
                If currRow.Cells(1).Text = prevRow.Cells(1).Text Then
                    currRow.Cells(1).RowSpan = IIf(prevRow.Cells(1).RowSpan < 2, 2, prevRow.Cells(1).RowSpan + 1)
                    prevRow.Cells(1).Visible = False
                    currRow.Cells(2).RowSpan = IIf(prevRow.Cells(1).RowSpan < 2, 2, prevRow.Cells(1).RowSpan + 1)
                    prevRow.Cells(2).Visible = False
                End If
            End If
        Next
    Next
End Sub

Protected Sub Gridview1_PreRender(ByVal sender As Object, ByVal e As EventArgs) Handles Gridview1.PreRender
    mergeRows(Gridview1)
End Sub