C#泛型之List操作示例
{
label1.Text = "";
/*
ArrayList AL = new ArrayList(3);
TestData temp = new TestData(1);
AL.Add(temp);
AL.Add(new TestData(2));
AL.Add(new TestData(3));
foreach (TestData item in AL)
{
label1.Text += item.Val.ToString() + " ";
item.Val += 1;
}
foreach (TestData item in AL)
{
label1.Text += item.Val.ToString() + " ";
}
*/
List<Racer> racers;
List<Racer> racers2;
FindRacer finder;
//--------------------------------------------------------------------------------
//生成泛型对象
racers = new List<Racer>();
racers.Add(new Racer("M J", "L"));
racers.Add(new Racer("AD3 R", "OK3"));
racers.Add(new Racer("M2 O", "L2"));
racers.Add(new Racer("AD2 Q", "OK2"));
racers.Add(new Racer("M1 W", "L"));
racers.Add(new Racer("AD4 A", "OK4"));
racers.Add(new Racer("AD1 L", "OK1"));
//跌代显示泛型对象所有元素
label1.Text += "\n跌代显示泛型对象所有元素\n";
foreach (Racer item in racers)
{
label1.Text += item.ToString() + " ";
}
//--------------------------------------------------------------------------------
/*
List<T>查找对象:Preadcate<T>是一个委托,它引用一个谓词方法.
public T Find<Predicate<T> match);
public List<T> FindAll<Predicate<T> match);
*/
//委托查找所有满足条件的元素
label1.Text += "\nFindAll(Car==\"L\")\n";
finder = new FindRacer("L");
foreach(Racer item in racers.FindAll(new Predicate<Racer>(finder.DrivingCarPredicate)))
{
label1.Text += item.ToString() + " ";
}
label1.Text += "\nFindAll(Car==\"L\")将结果赋给其它泛型对象\n";
racers2 = racers.FindAll(new Predicate<Racer>(finder.DrivingCarPredicate));//返回泛型对象
foreach (Racer item in racers2)
{
label1.Text += item.ToString() + " ";
}
//委托查找一个元素(找到的第一个元素)
label1.Text += "\nFind(Car==\"L\")\n";
finder = new FindRacer("L2");
label1.Text += racers.Find(new Predicate<Racer>(finder.DrivingCarPredicate)).ToString();
//将查找出的元素做修改
racers.Find(new Predicate<Racer>(finder.DrivingCarPredicate)).Car = "L";
label1.Text += "\n将查找出元素修改过后\n";
finder = new FindRacer("L");
foreach (Racer item in racers.FindAll(new Predicate<Racer>(finder.DrivingCarPredicate)))
{
label1.Text += item.ToString() + " ";
}
//--------------------------------------------------------------------------------
/*
List<T>.ForEach()可以用于对每个元素执行一些操作.
它使用Action<T>委托对集合中的每个元素执行操作.Action<T>委托返回的类型是void.
*/
racers.ForEach(delegate(Racer r) { r.Car += "_CAR"; });
label1.Text += "\nList<T>.ForEach()全部修改对象\n";
foreach (Racer item in racers)
{
label1.Text += item.ToString() + " ";
}
//--------------------------------------------------------------------------------
/*
List<T>.Sort对元素进行排序
*/
//public void List<T>.Sort(Comparison<T>), 是一个委托方法,该方法带两个T类型参数;
racers.Sort(delegate(Racer r1, Racer r2) { return r1.Car.CompareTo(r2.Car); });
label1.Text += "\n 排序public void List<T>.Sort(Comparison<T>)\n";
foreach (Racer item in racers)
{
label1.Text += item.ToString() + " ";
}
//public void List<T>.Sort(IComparer<T>)
racers.Sort(new RacerComparer(RacerComparer.CompareType.Name));
label1.Text += "\n 排序public void List<T>.Sort(IComparer<T>)\n";
foreach (Racer item in racers)
{
label1.Text += item.ToString() + " ";
}
//--------------------------------------------------------------------------------
/*
类型转换
*/
List<Person> persons = racers.ConvertAll<Person>(delegate(Racer r)
{
int ixSeparator = r.Name.LastIndexOf(' ') + 1;
string lastname = r.Name.Substring(ixSeparator, r.Name.Length - ixSeparator);
string firstname = r.Name.Substring(0, ixSeparator - 1);
return(new Person(firstname, lastname));
});
label1.Text += "\n List<T>.ConvertAll类型转换\n";
foreach (Person item in persons)
{
label1.Text += item.ToString() + " ";
}
label1.Text += "\n 类型转换后的源数据\n";
foreach (Racer item in racers)
{
label1.Text += item.ToString() + " ";
}
//--------------------------------------------------------------------------------
}
//--------------------------------------------------------------------------------
//实体类
class Racer
{
private string name;
public string Name
{
get
{
return (name);
}
}
private string car;
public string Car
{
get
{
return (car);
}
set
{
car = value;
}
}
public Racer(string name, string car)
{
this.name = name;
this.car = car;
}
public override string ToString()
{
return name + "," + car;
}
}
//--------------------------------------------------------------------------------
//查找类
class FindRacer
{
private string car;
public FindRacer(string car)
{
this.car = car;
}
public bool DrivingCarPredicate(Racer racer)
{
return (racer.Car == car);
}
}
//排序类
class RacerComparer : IComparer<Racer>
{
public enum CompareType
{
Name, Car
}
private CompareType compareType;
public RacerComparer(CompareType compareType)
{
this.compareType = compareType;
}
public int Compare(Racer x, Racer y)
{
int result = 0;
switch (compareType)
{
case CompareType.Name:
{
result = x.Name.CompareTo(y.Name);
break;
}
case CompareType.Car:
{
result = x.Car.CompareTo(x.Car);
break;
}
}
return (result);
}
}
//--------------------------------------------------------------------------------
//类型转换类
public class Person
{
private string firstname;
private string lastname;
public Person(string firstname, string lastname)
{
this.firstname = firstname;
this.lastname = lastname;
}
public override string ToString()
{
return (firstname + "." + lastname);
}
}
