MSDN上关于泛型的例子

using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

 

namespace Generics_CSharp

{

    // 尖括号中的类型参数 T

    public class MyList<T> : IEnumerable<T>

    {

        protected Node head;

        protected Node current = null;

 

        // 嵌套类型也是 T 上的泛型

        protected class Node

        {

            public Node next;

            // T 作为私有成员数据类型。

            private T data;

            // 在非泛型构造函数中使用的 T

            public Node(T t)

            {

                next = null;

                data = t;

            }

            public Node Next

            {

                get { return next; }

                set { next = value; }

            }

            // T 作为属性的返回类型。

            public T Data

            {

                get { return data; }

                set { data = value; }

            }

        }

 

        public MyList()

        {

            head = null;

        }

 

        // T 作为方法参数类型。

        public void AddHead(T t)

        {

            Node n = new Node(t);

            n.Next = head;

            head = n;

        }

 

        // 实现 GetEnumerator 以返回 IEnumerator<T>,从而启用列表的

        // foreach 迭代。请注意,在 C# 2.0 中,

        // 不需要实现 Current MoveNext

        // 编译器将创建实现 IEnumerator<T> 的类。

        public IEnumerator<T> GetEnumerator()

        {

            Node current = head;

 

            while (current != null)

            {

                yield return current.Data;

                current = current.Next;

            }

        }

 

        // 必须实现此方法,因为

        // IEnumerable<T> 继承 IEnumerable

        IEnumerator IEnumerable.GetEnumerator()

        {

            return GetEnumerator();

        }

    }

 

// where T : IComparable<T> 表示这个T类型必须实现了Icomparable接口

    public class SortedList<T> : MyList<T> where T : IComparable<T>

    {

        // 一个未优化的简单排序算法,

        // 该算法从低到高对列表元素排序:

        public void BubbleSort()

        {

            if (null == head || null == head.Next)

                return;

 

            bool swapped;

            do

            {

                Node previous = null;

                Node current = head;

                swapped = false;

 

                while (current.next != null)

                {

                    // 由于需要调用此方法,因此,SortedList

                    // 类在 IEnumerable<T> 上是受约束的

                    if (current.Data.CompareTo(current.next.Data) > 0)

                    {

                        Node tmp = current.next;

                        current.next = current.next.next;

                        tmp.next = current;

 

                        if (previous == null)

                        {

                            head = tmp;

                        }

                        else

                        {

                            previous.next = tmp;

                        }

                        previous = tmp;

                        swapped = true;

                    }

 

                    else

                    {

                        previous = current;

                        current = current.next;

                    }

 

                }// 结束 while

            } while (swapped);

        }

    }

 

    // 一个将自身作为类型参数来实现 IComparable<T> 的简单类,

    // 是对象中的

    // 常用设计模式,这些对象

    // 存储在泛型列表中。

    public class Person : IComparable<Person>

    {

        string name;

        int age;

 

        public Person(string s, int i)

        {

            name = s;

            age = i;

        }

 

        // 这会使列表元素

        // age 值排序。

        public int CompareTo(Person p)

        {

            return age - p.age;

        }

 

        public override string ToString()

        {

            return name + ":" + age;

        }

 

        // 必须实现 Equals

        public bool Equals(Person p)

        {

            return (this.age == p.age);

        }

    }

 

    class Generics

    {

        static void Main(string[] args)

        {

            // 声明并实例化一个新的范型 SortedList 类。

            // Person 是类型参数。

            SortedList<Person> list = new SortedList<Person>();

 

            // 创建 name age 值以初始化 Person 对象。

            string[] names = new string[] { "Franscoise", "Bill", "Li", "Sandra", "Gunnar", "Alok", "Hiroyuki", "Maria", "Alessandro", "Raul" };

            int[] ages = new int[] { 45, 19, 28, 23, 18, 9, 108, 72, 30, 35 };

 

            // 填充列表。

            for (int x = 0; x < names.Length; x++)

            {

                list.AddHead(new Person(names[x], ages[x]));

            }

 

            Console.WriteLine("Unsorted List:");

            // 打印出未排序的列表。

            foreach (Person p in list)

            {

                Console.WriteLine(p.ToString());

            }

 

            // 对列表进行排序。

            list.BubbleSort();

 

            Console.WriteLine(String.Format("{0}Sorted List:", Environment.NewLine));

            // 打印出排序的列表。

            foreach (Person p in list)

            {

                Console.WriteLine(p.ToString());

            }

 

            Console.WriteLine("Done");

        }

    }

 

}

 

 

 

 

 

using System;

using System.Collections;

public class List

{

    public static IEnumerable Power(int number, int exponent)

    {

        int counter = 0;

        int result = 1;

        while (counter++ < exponent)

        {

            result = result * number;

            yield return result;

        }

    }

 

    static void Main()

    {

        // Display powers of 2 up to the exponent 8:

        foreach (int i in Power(2, 8))

        {

            Console.Write("{0} ", i);

        }

    }

}

 

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posted @ 2007-09-05 22:44  peak  阅读(369)  评论(0编辑  收藏  举报