How to convert Excel sheet column names into numbers? [duplicate]

Answer 1

Source code:

namespace XLS
{
/// 

/// Represents a single cell in a excell sheet
/// 
public struct Cell
{
    private long row;
    private long column;
    private string columnAddress;
    private string address;
    private bool dataChange;

    /// 

    /// Initializes a new instance of the XLS.Cell 
    /// class with the specified row and column of excel worksheet
    /// 
    /// The row index of a cell
    /// The column index of a cell
    public Cell(long row, long column)
    {
        this.row = row;
        this.column = column;
        dataChange = true;
        address = string.Empty;
        columnAddress = string.Empty;
    }

    /// 

    /// Initializes a new instance of the XLS.Cell
    /// class with the specified address of excel worksheet
    /// 
    /// The adress of a cell
    public Cell(string address)
    {
        this.address = address;
        dataChange = false;
        row = GetRow(address);
        columnAddress = GetColumnAddress(address);
        column = GetColumn(columnAddress);
    }

    /// 

    /// Gets or sets the row of this XLS.Cell
    /// 
    public long Row
    {
        get { return row <= 0 ? 1 : row; }
        set { row = value; dataChange = true; }
    }

    /// 

    /// Gets or sets the column of this XLS.Cell
    /// 
    public long Column
    {
        get { return column <= 0 ? 1 : column; }
        set { column = value; dataChange = true; }
    }

    /// 

    /// Gets or sets the address of this XLS.Cell
    /// 
    public string Address
    {
        get { return dataChange ? ToAddress() : address; }
        set
        {
            address = value;
            row = GetRow(address);
            column = GetColumn(address);
        }
    }

    /// 

    /// Gets the column address of this XLS.Cell
    /// 
    public string ColumnAddress
    {
        get { return GetColumnAddress(Address); }
        private set { columnAddress = value; }
    }

    #region Private Methods

    private static long GetRow(string address)
    {
        return long.Parse(address.Substring(GetStartIndex(address)));
    }

    private static string GetColumnAddress(string address)
    {
        return address.Substring(0, GetStartIndex(address)).ToUpperInvariant();
    }

    private static long GetColumn(string columnAddress)
    {
        char[] characters = columnAddress.ToCharArray();
        int sum = 0;
        for (int i = 0; i < characters.Length; i++)
        {
            sum *= 26;
            sum += (characters[i] - 'A' + 1);
        }

        return (long)sum;
    }

    private static int GetStartIndex(string address)
    {
        return address.IndexOfAny("123456789".ToCharArray());
    }

    private string ToAddress()
    {
        string indexToString = string.Empty;

        if (Column > 26)
        {
            indexToString = ((char)(65 + (int)((Column - 1) / 26) - 1)).ToString();
        }

        indexToString += (char)(65 + ((Column - 1) % 26));

        dataChange = false;
        return indexToString + Row;
    }

    #endregion
}

}