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

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

其他回答

f#版本的各种方式

let rec getExcelColumnName x  = if x<26 then int 'A'+x|>char|>string else (x/26-1|>c)+ c(x%26)

对不起,最小化,正在开发一个更好的https://stackoverflow.com/a/4500043/57883版本

相反的方向:

// return values start at 0
let getIndexFromExcelColumnName (x:string) =
    let a = int 'A'
    let fPow len i =
        Math.Pow(26., len - 1 - i |> float)
        |> int

    let getValue len i c = 
        int c - a + 1 * fPow len i
    let f i = getValue x.Length i x.[i]
    [0 .. x.Length - 1]
    |> Seq.map f
    |> Seq.sum
    |> fun x -> x - 1

以下是Graham在Powershell中的代码:

function ConvertTo-ExcelColumnID {
param (
    [parameter(Position = 0,
        HelpMessage = "A 1-based index to convert to an excel column ID. e.g. 2 => 'B', 29 => 'AC'",
        Mandatory = $true)]
    [int]$index
);

[string]$result = '';
if ($index -le 0 ) {
    return $result;
}

while ($index -gt 0) {
    [int]$modulo = ($index - 1) % 26;
    $character = [char]($modulo + [int][char]'A');
    $result = $character + $result;
    [int]$index = ($index - $modulo) / 26;
}

return $result;

}

我是这样做的:

private string GetExcelColumnName(int columnNumber)
{
    string columnName = "";

    while (columnNumber > 0)
    {
        int modulo = (columnNumber - 1) % 26;
        columnName = Convert.ToChar('A' + modulo) + columnName;
        columnNumber = (columnNumber - modulo) / 26;
    } 

    return columnName;
}

下面是一个基于零的列索引的更简单的解决方案

 public static string GetColumnIndexNumberToExcelColumn(int columnIndex)
        {
            int offset = columnIndex % 26;
            int multiple = columnIndex / 26;

            int initialSeed = 65;//Represents column "A"
            if (multiple == 0)
            {
                return Convert.ToChar(initialSeed + offset).ToString();
            }

            return $"{Convert.ToChar(initialSeed + multiple - 1)}{Convert.ToChar(initialSeed + offset)}";
        }
    public string ToBase26(int number)
    {
        if (number < 0) return String.Empty;

        int remainder = number % 26;
        int value = number / 26;

        return value == 0 ?
            String.Format("{0}", Convert.ToChar(65 + remainder)) :
            String.Format("{0}{1}", ToBase26(value - 1), Convert.ToChar(65 + remainder));
    }