一，一個賽車手的類表述了賽車手的姓名，國籍，獲獎情況等信息
[Serializable]
public class Racer : IComparable, IFormattable
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Wins { get; set; }
public string Country { get; set; }
public int Starts { get; set; }
public string[] Cars { get; set; }
public int[] Years { get; set; }
public override string ToString()
{
return string.Format("{0} {1}", FirstName, LastName);
}
public string ToString(string format)
{
return ToString(format, null);
}
public string ToString(string format, IFormatProvider formatProvider)
{
switch (format)
{
case null:
case "N":
return ToString();
case "F":
return FirstName;
case "L":
return LastName;
case "A":
return String.Format("{0} {1}, {2}; starts: {3}, wins: {4}",
FirstName, LastName, Country, Starts, Wins);
default:
throw new FormatException(String.Format(
"Format {0} not supported", format));
}
}
public int CompareTo(Racer other)
{
return this.LastName.CompareTo(other.LastName);
}
}
二，生成賽車手List的類，提供一個方法生成List
public class Formula1 { public static IList GetChampions() { List racers = new List(40); racers.Add(new Racer() { FirstName = "Nino", LastName = "Farina", Country = "Italy", Starts = 33, Wins = 5, Years = new int[] { 1950 }, Cars = new string[] { "Alfa Romeo" } }); racers.Add(new Racer() { FirstName = "Alberto", LastName = "Ascari", Country = "Italy", Starts = 32, Wins = 10, Years = new int[] { 1952, 1953 }, Cars = new string[] { "Ferrari" } }); racers.Add(new Racer() { FirstName = "Juan Manuel", LastName = "Fangio", Country = "Argentina", Starts = 51, Wins = 24, Years = new int[] { 1951, 1954, 1955, 1956, 1957 }, Cars = new string[] { "Alfa Romeo", "Maserati", "Mercedes", "Ferrari" } }); racers.Add(new Racer() { FirstName = "Mike", LastName = "Hawthorn", Country = "UK", Starts = 45, Wins = 3, Years = new int[] { 1958 }, Cars = new string[] { "Ferrari" } }); racers.Add(new Racer() { FirstName = "Phil", LastName = "Hill", Country = "USA", Starts = 48, Wins = 3, Years = new int[] { 1961 }, Cars = new string[] { "Ferrari" } }); racers.Add(new Racer() { FirstName = "John", LastName = "Surtees", Country = "UK", Starts = 111, Wins = 6, Years = new int[] { 1964 }, Cars = new string[] { "Ferrari" } }); racers.Add(new Racer() { FirstName = "Jim", LastName = "Clark", Country = "UK", Starts = 72, Wins = 25, Years = new int[] { 1963, 1965 }, Cars = new string[] { "Lotus" } }); racers.Add(new Racer() { FirstName = "Jack", LastName = "Brabham", Country = "Australia", Starts = 125, Wins = 14, Years = new int[] { 1959, 1960, 1966 }, Cars = new string[] { "Cooper", "Brabham" } }); racers.Add(new Racer() { FirstName = "Denny", LastName = "Hulme", Country = "New Zealand", Starts = 112, Wins = 8, Years = new int[] { 1967 }, Cars = new string[] { "Brabham" } }); racers.Add(new Racer() { FirstName = "Graham", LastName = "Hill", Country = "UK", Starts = 176, Wins = 14, Years = new int[] { 1962, 1968 }, Cars = new string[] { "BRM", "Lotus" } }); racers.Add(new Racer() { FirstName = "Jochen", LastName = "Rindt", Country = "Austria", Starts = 60, Wins = 6, Years = new int[] { 1970 }, Cars = new string[] { "Lotus" } }); racers.Add(new Racer() { FirstName = "Jackie", LastName = "Stewart", Country = "UK", Starts = 99, Wins = 27, Years = new int[] { 1969, 1971, 1973 }, Cars = new string[] { "Matra", "Tyrrell" } }); racers.Add(new Racer() { FirstName = "Emerson", LastName = "Fittipaldi", Country = "Brazil", Starts = 143, Wins = 14, Years = new int[] { 1972, 1974 }, Cars = new string[] { "Lotus", "McLaren" } }); racers.Add(new Racer() { FirstName = "James", LastName = "Hunt", Country = "UK", Starts = 91, Wins = 10, Years = new int[] { 1976 }, Cars = new string[] { "McLaren" } }); racers.Add(new Racer() { FirstName = "Mario", LastName = "Andretti", Country = "USA", Starts = 128, Wins = 12, Years = new int[] { 1978 }, Cars = new string[] { "Lotus" } }); racers.Add(new Racer() { FirstName = "Jody", LastName = "Scheckter", Country = "South Africa", Starts = 112, Wins = 10, Years = new int[] { 1979 }, Cars = new string[] { "Ferrari" } }); racers.Add(new Racer() { FirstName = "Alan", LastName = "Jones", Country = "Australia", Starts = 115, Wins = 12, Years = new int[] { 1980 }, Cars = new string[] { "Williams" } }); racers.Add(new Racer() { FirstName = "Keke", LastName = "Rosberg", Country = "Finland", Starts = 114, Wins = 5, Years = new int[] { 1982 }, Cars = new string[] { "Williams" } }); racers.Add(new Racer() { FirstName = "Niki", LastName = "Lauda", Country = "Austria", Starts = 173, Wins = 25, Years = new int[] { 1975, 1977, 1984 }, Cars = new string[] { "Ferrari", "McLaren" } }); racers.Add(new Racer() { FirstName = "Nelson", LastName = "Piquet", Country = "Brazil", Starts = 204, Wins = 23, Years = new int[] { 1981, 1983, 1987 }, Cars = new string[] { "Brabham", "Williams" } }); racers.Add(new Racer() { FirstName = "Ayrton", LastName = "Senna", Country = "Brazil", Starts = 161, Wins = 41, Years = new int[] { 1988, 1990, 1991 }, Cars = new string[] { "McLaren" } }); racers.Add(new Racer() { FirstName = "Nigel", LastName = "Mansell", Country = "UK", Starts = 187, Wins = 31, Years = new int[] { 1992 }, Cars = new string[] { "Williams" } }); racers.Add(new Racer() { FirstName = "Alain", LastName = "Prost", Country = "France", Starts = 197, Wins = 51, Years = new int[] { 1985, 1986, 1989, 1993 }, Cars = new string[] { "McLaren", "Williams" } }); racers.Add(new Racer() { FirstName = "Damon", LastName = "Hill", Country = "UK", Starts = 114, Wins = 22, Years = new int[] { 1996 }, Cars = new string[] { "Williams" } }); racers.Add(new Racer() { FirstName = "Jacques", LastName = "Villeneuve", Country = "Canada", Starts = 165, Wins = 11, Years = new int[] { 1997 }, Cars = new string[] { "Williams" } }); racers.Add(new Racer() { FirstName = "Mika", LastName = "Hakkinen", Country = "Finland", Starts = 160, Wins = 20, Years = new int[] { 1998, 1999 }, Cars = new string[] { "McLaren" } }); racers.Add(new Racer() { FirstName = "Michael", LastName = "Schumacher", Country = "Germany", Starts = 250, Wins = 91, Years = new int[] { 1994, 1995, 2000, 2001, 2002, 2003, 2004 }, Cars = new string[] { "Benetton", "Ferrari" } }); racers.Add(new Racer() { FirstName = "Fernando", LastName = "Alonso", Country = "Spain", Starts = 105, Wins = 19, Years = new int[] { 2005, 2006 }, Cars = new string[] { "Renault" } }); racers.Add(new Racer() { FirstName = "Kimi", LastName = "Räikkönen", Country = "Finland", Starts = 122, Wins = 15, Years = new int[] { 2007 }, Cars = new string[] { "Ferrari" } }); return racers; } }
三，示例代碼
static class Program { static void Main(string[] args) { //使用普通的委託 List racers = new List(Formula1.GetChampions()); List brazilRacers = racers.FindAll(IsBrazilHandle); brazilRacers.Sort(SortRacersHandle); foreach (Racer r in brazilRacers) { Console.WriteLine("使用普通的委託"); Console.WriteLine("{0:A}", r); r.PutInfo(DateTime.Now); } //使用匿名委委託
racers = new List(Formula1.GetChampions()); brazilRacers = racers.FindAll( delegate(Racer r) { return r.Country == "Brazil"; }); brazilRacers.Sort( delegate(Racer r1, Racer r2) { return r2.Wins.CompareTo(r1.Wins); } ); foreach (Racer r in brazilRacers) { Console.WriteLine("使用匿名代理"); Console.WriteLine("{0:A}", r); r.PutInfo(DateTime.Now); } //使用LINQ類提供的擴展方法 racers = new List(Formula1.GetChampions()); brazilRacers.Where( delegate(Racer r) { return r.Country == "Brazil"; }); brazilRacers.OrderByDescending( delegate(Racer r) { return r.Wins; }); brazilRacers.Select( delegate(Racer r) { return r; }); foreach (Racer r in brazilRacers) { Console.WriteLine("LINQ類的擴展方法"); Console.WriteLine("{0:A}", r); r.PutInfo(DateTime.Now); } //運用Lamda表括達式 racers = new List(Formula1.GetChampions()); racers.Where(r => r.Country == "Brazil"); racers.OrderByDescending(r => r.Wins); racers.Select(r => r); foreach (Racer r in brazilRacers) { Console.WriteLine(); Console.WriteLine("Lamda表括達式{0:A}", r); r.PutInfo(DateTime.Now); } //最終演變爲LINQ查詢 racers = new List(Formula1.GetChampions()); var query = from r in racers where r.Country == "Brazil" orderby r.Wins descending select r; foreach (Racer r in query) { Console.WriteLine(); Console.WriteLine("LINQ查詢{0:A}", r); r.PutInfo(DateTime.Now); } Console.Read(); } /// /// 擴展方法實例 /// 調用擴展方法只是調用靜態方法的一種新語法 /// /// public static void PutInfo(this Racer r, DateTime dt) { Console.WriteLine("{0}", dt.ToLongTimeString()); } /// /// 用於查找 /// public static Predicate IsBrazilHandle = IsBrazil; public static bool IsBrazil(Racer r) { if (r.Country == "Brazil") { return true; } else { return false; } } /// /// 用於排序 /// public static Comparison SortRacersHandle = new Comparison(SortRacers); public static int SortRacers(Racer r1, Racer r2) { int index = r2.Wins.CompareTo(r1.Wins); return index; } }
說明：該示例參照C#高級編程中關於LINQ的講解