C# IFormattable 接口重写

             1
            public
            class Racer : IComparable<Racer>, IFormattable
 2  {
 3publicint Id { get; privateset; }
 4publicstring FirstName { get; set; }
 5publicstring LastName { get; set; }
 6publicstring Country { get; set; }
 7publicint Wins { get; set; }
 8 9public Racer(int id, string firstName, string lastName, string country = null, int wins = 0)
10    {
11this.Id = id;
12this.FirstName = firstName;
13this.LastName = lastName;
14this.Country = country;
15this.Wins = wins;
16    }
1718publicoverridestring ToString()
19    {
20return String.Format("{0} {1}", FirstName, LastName);
21    }
2223publicstring ToString(string format, IFormatProvider formatProvider)
24    {
25if (format == null) format = "N";
26switch (format.ToUpper())
27      {
28case"N": // name29return ToString();
30case"F": // first name31return FirstName;
32case"L": // last name33return LastName;
34case"W": // Wins35return String.Format("{0}, Wins: {1}", ToString(), Wins);
36case"C": // Country37return String.Format("{0}, Country: {1}", ToString(), Country);
38case"A": // All39return String.Format("{0}, {1} Wins: {2}", ToString(), Country, Wins);
40default:
41thrownew FormatException(String.Format(formatProvider,
42"Format {0} is not supported", format));
43      }
44    }
4546publicstring ToString(string format)
47    {
48return ToString(format, null);
49    }
5051publicint CompareTo(Racer other)
52    {
53int compare = this.LastName.CompareTo(other.LastName);
54if (compare == 0)
55returnthis.FirstName.CompareTo(other.FirstName);
56return compare;
57    }
58   }