How to implement column self-naming from its index?

Question

I wish to be able to instantiate my Cell class while naming the cell instance with such name as "A", "B", "C", etc. just like in an Excel spreadsheet.

I have my Cell class like so:

public class Cell {
    public Cell(Range nativeCell) {
        NativeCell = nativeCell;
    }

    public Range NativeCell { get; private set; }
}

And my Sheet class:

public class Sheet {
    private IDictionary<string, Cell> _cells;

    public Sheet(Worksheet nativeSheet) {
        NativeSheet = nativeSheet;

        _cells = new Dictionary<string, Cell>();

        for (int rowIndex = 1; rowIndex <= NativeSheet.Rows.Count; ++rowIndex)
            for (int colIndex = 1; colIndex <= NativeSheet.Columns.Count; ++colIndex) {
                ICell newCell = new Cell(NativeSheet.Cells(rowIndex, colIndex));
                newCell.Name = ?? // This name should look like "A1", "B1", "AA3", "CB20", etc.
                Cells.Add(newCell.Name, newCell);
            }
    }

    public IDictionary<string, Cell> Cells {
        get {
            return _cells;
        }
    }

    public Worksheet NativeSheet { get; private set; }
}

I would need to generate a name based on the alphabetic letters and double and triple them once I encounter the last alphabet letter 'Z'. The algorithm would have to generate the letters that I would concatenate with the rowIndex value that would result to this naming strategy such as Excel.

The letters would be:

A, B, C, D...Z, AA, AB, AC...AZ, BA, BB, BC...BZ, CA...XAA, XAB, XAC...

While we clearly know that colIndex value 1 will definitely designate column "A", value 2 = "B", value 3 = "C", etc.

My problem is particularly when we double the letters.

Do you have any idea on how I could achieve this in the simplest possible form?

Thanks! =)

Answer 1

Here is this. Translate a column index into an Excel Column Name

Shouldn't be to hard to make it recursive and give you exactly what you need. I hope this helps.