ExcelNumberFormat

.NET library to parse ECMA-376 number format strings and format values like Excel and other spreadsheet softwares.

Install via NuGet

If you want to include ExcelNumberFormat in your project, you can install it directly from NuGet

To install ExcelNumberFormat, run the following command in the Package Manager Console

PM> Install-Package ExcelNumberFormat

Usage

var format = new NumberFormat("#.##");
Console.WriteLine(format.Format(1234.56, CultureInfo.InvariantCulture));

Features

• Parses and formats most custom number formats as expected: decimal, percent, thousands, exponential, fraction, currency, date/time, duration, text.
• Supports multiple sections with conditions.
• Formats values with relevant constants from CultureInfo.
• Formats dates and durations using DateTime and TimeSpan values instead of numeric values like Excel.
• Targets net20 and netstandard1.0 for max compatibility.

Formatting .NET types

The Format() method takes a value of type object as parameter. Internally, the value is cast or converted to a specific .NET type depending on the kind of number format:

Format Kind	Example	.NET type	Conversion strategy
Number	0.00	double	Convert.ToDouble()
Fraction	0/0	double	Convert.ToDouble()
Exponent	#0.0E+0	double	Convert.ToDouble()
Date/Time	hh:mm	DateTime	Convert.ToDateTime()
Duration	[hh]:mm	TimeSpan	Cast to TimeSpan
General	General	(any)	Convert.ToString()
Text	;;;"Text: "@	string	Convert.ToString()

In case of errors, Format() returns the value from Convert.ToString().

TODO/notes

• 'General' is formatted with .ToString() instead of Excel conventions.
• No errors: Invalid format strings and incompatible input values are formatted with .ToString().
• No color information.
• Variable width space is returned as regular space.
• Repeat-to-fill characters are printed once, not repeated.
• No alignment hinting.
• No date conditions.