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。
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
巧合和优雅的Ruby版本:
def col_name(col_idx)
name = ""
while col_idx>0
mod = (col_idx-1)%26
name = (65+mod).chr + name
col_idx = ((col_idx-mod)/26).to_i
end
name
end
其他回答
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;
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
到目前为止,所有的解决方案都包含迭代或递归,这让我感到惊讶。
这是我的解,在常数时间内运行(没有循环)。此解决方案适用于所有可能的Excel列,并检查输入是否可以转换为Excel列。可能的列在[A, XFD]或[1,16384]范围内。(这取决于你的Excel版本)
private static string Turn(uint col)
{
if (col < 1 || col > 16384) //Excel columns are one-based (one = 'A')
throw new ArgumentException("col must be >= 1 and <= 16384");
if (col <= 26) //one character
return ((char)(col + 'A' - 1)).ToString();
else if (col <= 702) //two characters
{
char firstChar = (char)((int)((col - 1) / 26) + 'A' - 1);
char secondChar = (char)(col % 26 + 'A' - 1);
if (secondChar == '@') //Excel is one-based, but modulo operations are zero-based
secondChar = 'Z'; //convert one-based to zero-based
return string.Format("{0}{1}", firstChar, secondChar);
}
else //three characters
{
char firstChar = (char)((int)((col - 1) / 702) + 'A' - 1);
char secondChar = (char)((col - 1) / 26 % 26 + 'A' - 1);
char thirdChar = (char)(col % 26 + 'A' - 1);
if (thirdChar == '@') //Excel is one-based, but modulo operations are zero-based
thirdChar = 'Z'; //convert one-based to zero-based
return string.Format("{0}{1}{2}", firstChar, secondChar, thirdChar);
}
}
递归很简单。
public static string GetStandardExcelColumnName(int columnNumberOneBased)
{
int baseValue = Convert.ToInt32('A');
int columnNumberZeroBased = columnNumberOneBased - 1;
string ret = "";
if (columnNumberOneBased > 26)
{
ret = GetStandardExcelColumnName(columnNumberZeroBased / 26) ;
}
return ret + Convert.ToChar(baseValue + (columnNumberZeroBased % 26) );
}
在查看了这里提供的所有版本后,我决定自己使用递归来做一个。
这是我的vb.net版本:
Function CL(ByVal x As Integer) As String
If x >= 1 And x <= 26 Then
CL = Chr(x + 64)
Else
CL = CL((x - x Mod 26) / 26) & Chr((x Mod 26) + 1 + 64)
End If
End Function