数字转换成字母帮助类

C# 实现Excel（导出导入）非常实用的将数字转换成字母

   

///

/// 需要转换的行或者列
///

///
///
private static string NunberToChar(int index)
{

index = index - 1;
if (index < 0) { throw new Exception("invalid parameter"); }

List chars = new List();
do
{
if (chars.Count > 0) index--;
chars.Insert(0, ((char)(index % 26 + (int)'A')).ToString());
index = (int)((index - index % 26) / 26);
} while (index > 0);

return String.Join(string.Empty, chars.ToArray());

}