c# – EPPlus – 按索引而不是按字母表示法处理多个列

''' <summary>
''' Allows you to reference a column by its numeric index rather than its alphabetic representation
''' </summary>
''' <param name="colNum">The index of the column to reference on in the worksheet.</param>
<System.Runtime.CompilerServices.Extension()> _
Public Function Columns(ByVal wks As ExcelWorksheet,ByVal colNum As Integer) As ExcelRange
    Dim ColName As String = ReturnColumnName(colNum)

    Return wks.Cells(ColName & ":" & ColName)
End Function


''' <summary>
''' Allows you to reference a column by its numeric index rather than its alphabetic representation
''' </summary>
''' <param name="StartColNum">The start col num.</param>
''' <param name="EndColNum">The end col num.</param>
<System.Runtime.CompilerServices.Extension()> _
Public Function Columns(ByVal wks As ExcelWorksheet,ByVal StartColNum As Integer,ByVal EndColNum As Integer) As ExcelRange
    Dim StartColName As String = ReturnColumnName(StartColNum)
    Dim EndColName As String = ReturnColumnName(EndColNum)

    Return wks.Cells(StartColName & ":" & EndColName)
End Function



Private Function ReturnColumnName(ByVal colNum As Integer) As String
    Dim d As Integer
    Dim m As Integer
    Dim Name As String

    d = colNum
    Name = ""

    Do While (d > 0)
        m = (d - 1) Mod 26
        Name = Chr(65 + m) + Name
        d = Int((d - m) / 26)
    Loop

    Return Name
End Function