Convert a number to a letter in C# for use in Microsoft Excel [duplicate]

Question

Possible Duplicate:
How to convert a column number (eg. 127) into an excel column (eg. AA)

Ok so I am writing a method which accepts a 2d array as a parameter. I want to put this 2d array onto an Excel worksheet but I need to work out the final cell location. I can get the height easily enough like so:

var height = data.GetLength(1); //`data` is the name of my 2d array

This gives me my Y axis but it's not so easy to get my X axis. Obviously I can get the number like so:

var width = data.GetLength(0);

This gives me a number, which I want to convert to a letter. So, for example, 0 is A, 1 is B and so on until we get to 26 which goes back to A again. I am sure that there is a simple way to do this but I have a total mental block.

What would you do?

Thanks

Answer 1

Here's a version that also handles two-letter columns (after column Z):

static string GetColumnName(int index)
{
    const string letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    var value = "";

    if (index >= letters.Length)
        value += letters[index / letters.Length - 1];

    value += letters[index % letters.Length];

    return value;
}