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

只是抛出一个简单的使用递归的两行c#实现,因为这里所有的答案似乎都比必要的复杂得多。

/// <summary>
/// Gets the column letter(s) corresponding to the given column number.
/// </summary>
/// <param name="column">The one-based column index. Must be greater than zero.</param>
/// <returns>The desired column letter, or an empty string if the column number was invalid.</returns>
public static string GetColumnLetter(int column) {
    if (column < 1) return String.Empty;
    return GetColumnLetter((column - 1) / 26) + (char)('A' + (column - 1) % 26);
}

其他回答

精炼原始的解决方案(在c#中):

public static class ExcelHelper
{
    private static Dictionary<UInt16, String> l_DictionaryOfColumns;

    public static ExcelHelper() {
        l_DictionaryOfColumns = new Dictionary<ushort, string>(256);
    }

    public static String GetExcelColumnName(UInt16 l_Column)
    {
        UInt16 l_ColumnCopy = l_Column;
        String l_Chars = "0ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String l_rVal = "";
        UInt16 l_Char;


        if (l_DictionaryOfColumns.ContainsKey(l_Column) == true)
        {
            l_rVal = l_DictionaryOfColumns[l_Column];
        }
        else
        {
            while (l_ColumnCopy > 26)
            {
                l_Char = l_ColumnCopy % 26;
                if (l_Char == 0)
                    l_Char = 26;

                l_ColumnCopy = (l_ColumnCopy - l_Char) / 26;
                l_rVal = l_Chars[l_Char] + l_rVal;
            }
            if (l_ColumnCopy != 0)
                l_rVal = l_Chars[l_ColumnCopy] + l_rVal;

            l_DictionaryOfColumns.ContainsKey(l_Column) = l_rVal;
        }

        return l_rVal;
    }
}

只是抛出一个简单的使用递归的两行c#实现,因为这里所有的答案似乎都比必要的复杂得多。

/// <summary>
/// Gets the column letter(s) corresponding to the given column number.
/// </summary>
/// <param name="column">The one-based column index. Must be greater than zero.</param>
/// <returns>The desired column letter, or an empty string if the column number was invalid.</returns>
public static string GetColumnLetter(int column) {
    if (column < 1) return String.Empty;
    return GetColumnLetter((column - 1) / 26) + (char)('A' + (column - 1) % 26);
}

谢谢你的回答!!帮助我想出了这些帮助函数,与我正在Elixir/Phoenix中工作的谷歌Sheets API进行一些交互

以下是我想到的(可能需要一些额外的验证和错误处理)

长生不老药:

def number_to_column(number) do
  cond do
    (number > 0 && number <= 26) ->
      to_string([(number + 64)])
    (number > 26) ->
      div_col = number_to_column(div(number - 1, 26))
      remainder = rem(number, 26)
      rem_col = cond do
        (remainder == 0) ->
          number_to_column(26)
        true ->
          number_to_column(remainder)
      end
      div_col <> rem_col
    true ->
      ""
  end
end

逆函数是:

def column_to_number(column) do
  column
    |> to_charlist
    |> Enum.reverse
    |> Enum.with_index
    |> Enum.reduce(0, fn({char, idx}, acc) ->
      ((char - 64) * :math.pow(26,idx)) + acc
    end)
    |> round
end

还有一些测试:

describe "test excel functions" do
  @excelTestData [{"A", 1}, {"Z",26}, {"AA", 27}, {"AB", 28}, {"AZ", 52},{"BA", 53}, {"AAA", 703}]

  test "column to number" do
    Enum.each(@excelTestData, fn({input, expected_result}) ->
      actual_result = BulkOnboardingController.column_to_number(input)
      assert actual_result == expected_result
    end)
  end

  test "number to column" do
    Enum.each(@excelTestData, fn({expected_result, input}) ->
      actual_result = BulkOnboardingController.number_to_column(input)
      assert actual_result == expected_result
    end)
  end
end

我正在尝试在Java中做同样的事情… 我写了以下代码:

private String getExcelColumnName(int columnNumber) {

    int dividend = columnNumber;
    String columnName = "";
    int modulo;

    while (dividend > 0)
    {
        modulo = (dividend - 1) % 26;

        char val = Character.valueOf((char)(65 + modulo));

        columnName += val;

        dividend = (int)((dividend - modulo) / 26);
    } 

    return columnName;
}

现在,一旦我用columnNumber = 29运行它,它给我的结果=“CA”(而不是“AC”) 有什么意见吗? 我知道我可以通过StringBuilder....反转它但看着格雷厄姆的回答,我有点困惑....

我今天必须做这个工作,我的实现使用递归:

private static string GetColumnLetter(string colNumber)
{
    if (string.IsNullOrEmpty(colNumber))
    {
        throw new ArgumentNullException(colNumber);
    }

    string colName = String.Empty;

    try
    {
        var colNum = Convert.ToInt32(colNumber);
        var mod = colNum % 26;
        var div = Math.Floor((double)(colNum)/26);
        colName = ((div > 0) ? GetColumnLetter((div - 1).ToString()) : String.Empty) + Convert.ToChar(mod + 65);
    }
    finally
    {
        colName = colName == String.Empty ? "A" : colName;
    }

    return colName;
}

该方法将数字视为字符串,而以“0”开头的数字(A = 0)