How to remove decimal separator if the decimal part is zero?

Question

I'm using ClosedXML to create a excel spreadsheet. The issue takes place while formatting cells, containg percentages.

The format I came up to is 0.##%.

It works well when the decimal part is not zero, it shows: 1,15%; but when it's integral-valued, it leaves the decimal separator visible, while hiding zeroes, for example: 5,%.

How can I make it hide the decimal separator as well?

Here is a small program, demonstrating the issue:

XLWorkbook wb = new XLWorkbook();
var ws = wb.AddWorksheet("test");

string format = "0.##%";

var cell = ws.Cell(1, 1);
cell.SetValue(5.2M / 100);
cell.Style.NumberFormat.Format = format;

cell = ws.Cell(1, 2);
cell.SetValue(5M / 100);
cell.Style.NumberFormat.Format = format;

wb.SaveAs("test.xlsx");

and the output is

Answer 1

Many thanks to Jason for the link to CLOSED XML: Conditional Formatting!

Thanks to this I managed to find the way to apply conditional formatting I needed:

cell.AddConditionalFormat()
    .WhenEquals(
        string.Format(
            "=TRUNC(${0}${1})", 
            cell.WorksheetColumn().ColumnLetter(),
            cell.WorksheetRow().RowNumber()))
    .NumberFormat
    .Format = "general\"%\"";

I gave up using percent format specifier, as it makes me divide by 100. From Excel Custom Number Formats:

% Percentage. Microsoft Excel multiplies by 100 and adds the % character.

Now I simply add % as a string, not as a format specifier.

So the main number format is 0.##\"%\", but when the value's decimal part is zero, I substitute the number format to the general one with % in the end using conditional formatting.