C # in a Nutshell, Second Edition

This interface provides a custom formatter, which returns string information for supplied objects based on custom criteria. The ICustomFormatter interface contains a single Format( ) method. This method accepts a format string and an IFormatProvider object and uses this criteria to determine which string to return for the specified object.

public interface ICustomFormatter { // Public Instance Methods public string Format (string format , object arg , IFormatProvider formatProvider ); }