GridView中2列表头合并，同列相同值的表格合并

       'GridView中2列表头合并
        Sub JoinHeader(ByVal gv As GridView, ByVal dt As DataTable, ByVal column As Integer)

            Dim baseCell As TableCell = New TableCell
            Dim nextCell As TableCell = New TableCell

            baseCell = gv.HeaderRow.Cells(column)
            nextCell = gv.HeaderRow.Cells(column + 1)
            baseCell.ColumnSpan = 2
            gv.HeaderRow.Cells.Remove(nextCell)

        End Sub

        'GridView中同列相同值的表格合并
        Sub JoinCells(ByVal gv As GridView, ByVal dt As DataTable, ByVal column As Integer)

            Dim numRow As Integer = dt.Rows.Count
            Dim baseNum As Integer = 0
            Dim nextNum As Integer = 0

            Dim baseCell As TableCell = New TableCell
            Dim nextCell As TableCell = New TableCell

            While baseNum < numRow - 1
                nextNum = baseNum + 1
                baseCell = gv.Rows(baseNum).Cells(column)
                baseCell.Text = dt.Rows(baseNum).Item(column).ToString

                While nextNum < numRow
                    nextCell = gv.Rows(nextNum).Cells(column)
                    nextCell.Text = dt.Rows(nextNum).Item(column).ToString

                    If baseCell.Text = nextCell.Text Then
                        If baseCell.RowSpan = 0 Then
                            baseCell.RowSpan = 2
                        Else
                            baseCell.RowSpan = baseCell.RowSpan + 1
                        End If
                        gv.Rows(nextNum).Cells.Remove(nextCell)
                        nextNum = nextNum + 1
                    Else
                        Exit While
                    End If
                End While

                baseNum = nextNum

            End While
        End Sub