如何在c#中将数值转换为Excel列名,而不使用直接从Excel中获取值的自动化。

Excel 2007的范围可能是1到16384,这是它支持的列数。结果值应以excel列名的形式出现,例如A、AA、AAA等。


当前回答

int nCol = 127;
string sChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string sCol = "";
while (nCol >= 26)
{
    int nChar = nCol % 26;
    nCol = (nCol - nChar) / 26;
    // You could do some trick with using nChar as offset from 'A', but I am lazy to do it right now.
    sCol = sChars[nChar] + sCol;
}
sCol = sChars[nCol] + sCol;

更新:Peter的评论是正确的。这就是我在浏览器中编写代码的结果。:-)我的解决方案是不编译,它是最左边的字母,它是在反向顺序构建字符串-现在都固定了。

除了bug之外,该算法基本上是将一个数字从10进制转换为26进制。

更新2:Joel Coehoorn是对的-上面的代码将返回AB为27。如果它是一个以26为底的实数,AA就等于A, Z之后的下一个数字就是BA。

int nCol = 127;
string sChars = "0ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string sCol = "";
while (nCol > 26)
{
    int nChar = nCol % 26;
    if (nChar == 0)
        nChar = 26;
    nCol = (nCol - nChar) / 26;
    sCol = sChars[nChar] + sCol;
}
if (nCol != 0)
    sCol = sChars[nCol] + sCol;

其他回答

这是编程测试中常见的问题。 它有一些约束条件: 每行最大列数= 702 输出应该有行号+列名,例如703的答案是2A。 (注意:我只是从另一个答案修改了现有的代码) 下面是相同的代码:

    static string GetExcelColumnName(long columnNumber)
    {
        //max number of column per row
        const long maxColPerRow = 702;
        //find row number
        long rowNum = (columnNumber / maxColPerRow);
        //find tierable columns in the row.
        long dividend = columnNumber - (maxColPerRow * rowNum);

        string columnName = String.Empty;

        long modulo;

        while (dividend > 0)
        {
            modulo = (dividend - 1) % 26;
            columnName = Convert.ToChar(65 + modulo).ToString() + columnName;
            dividend = (int)((dividend - modulo) / 26);
        }

        return rowNum+1+ columnName;
    }
}

这是一个javascript版本,根据格雷厄姆的代码

function (columnNumber) {
    var dividend = columnNumber;
    var columnName = "";
    var modulo;

    while (dividend > 0) {
        modulo = (dividend - 1) % 26;
        columnName = String.fromCharCode(65 + modulo) + columnName;
        dividend = parseInt((dividend - modulo) / 26);
    }

    return columnName;
};

我想在我使用的静态类中加入,用于在col index和col Label之间进行交互。我对ColumnLabel方法使用了修改后的可接受答案

public static class Extensions
{
    public static string ColumnLabel(this int col)
    {
        var dividend = col;
        var columnLabel = string.Empty;
        int modulo;

        while (dividend > 0)
        {
            modulo = (dividend - 1) % 26;
            columnLabel = Convert.ToChar(65 + modulo).ToString() + columnLabel;
            dividend = (int)((dividend - modulo) / 26);
        } 

        return columnLabel;
    }
    public static int ColumnIndex(this string colLabel)
    {
        // "AD" (1 * 26^1) + (4 * 26^0) ...
        var colIndex = 0;
        for(int ind = 0, pow = colLabel.Count()-1; ind < colLabel.Count(); ++ind, --pow)
        {
            var cVal = Convert.ToInt32(colLabel[ind]) - 64; //col A is index 1
            colIndex += cVal * ((int)Math.Pow(26, pow));
        }
        return colIndex;
    }
}

用这个…

30.ColumnLabel(); // "AD"
"AD".ColumnIndex(); // 30

JavaScript解决方案

/**
 * Calculate the column letter abbreviation from a 1 based index
 * @param {Number} value
 * @returns {string}
 */
getColumnFromIndex = function (value) {
    var base = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
    var remainder, result = "";
    do {
        remainder = value % 26;
        result = base[(remainder || 26) - 1] + result;
        value = Math.floor(value / 26);
    } while (value > 0);
    return result;
};

NodeJS实现:

/**
* getColumnFromIndex
* Helper that returns a column value (A-XFD) for an index value (integer).
* The column follows the Common Spreadsheet Format e.g., A, AA, AAA.
* See https://stackoverflow.com/questions/181596/how-to-convert-a-column-number-eg-127-into-an-excel-column-eg-aa/3444285#3444285
* @param numVal: Integer
* @return String
*/
getColumnFromIndex: function(numVal){
   var dividend = parseInt(numVal);
   var columnName = '';
   var modulo;
   while (dividend > 0) {
      modulo = (dividend - 1) % 26;
      columnName = String.fromCharCode(65 + modulo) + columnName;
      dividend = parseInt((dividend - modulo) / 26);
   }
   return columnName;
},

将excel列字母(如AA)转换为数字(如25)。反过来说:

/**
* getIndexFromColumn
* Helper that returns an index value (integer) for a column value (A-XFD).
* The column follows the Common Spreadsheet Format e.g., A, AA, AAA.
* See https://stackoverflow.com/questions/9905533/convert-excel-column-alphabet-e-g-aa-to-number-e-g-25
* @param strVal: String
* @return Integer
*/
getIndexFromColumn: function(val){
   var base = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', i, j, result = 0;
   for (i = 0, j = val.length - 1; i < val.length; i += 1, j -= 1) {
      result += Math.pow(base.length, j) * (base.indexOf(val[i]) + 1);
   }
   return result;
}