泛型类的功能

泛型类的功能：默认值、约束、继承、静态成员 。以从队列中读取文档为例

泛型继承：子类和基类泛型类型一致或指定基类的泛型类型

泛型的静态成员： 只能类的一个实例中共享

    public class StaticDemo<T>
        {
            public static int x;
        }
        public void test()
        {
             StaticDemo<string>.x = 4;
             StaticDemo<int>.x = 5;
             Console.WriteLine(StaticDemo<string>.x);  //输出4
             Console.WriteLine(StaticDemo<int>.x); //输出5
        }

文档接口(IDocument)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ListFunction
{
    public interface IDocument
    {
        /// <summary>
        /// 文章标题
        /// </summary>
        string Title
        {
            get;
            set;
        }

        /// <summary>
        /// 文章内容
        /// </summary>
        string Content
        {
            get;
            set;
        }
    }
}

文档类（Document）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ListFunction
{
    public class Document:IDocument
    {
        /// <summary>
        /// 文章标题
        /// </summary>
        public string Title
        {
            get;
            set;
        }

        /// <summary>
        /// 文章内容
        /// </summary>
        public string Content
        {
            get;
            set;
        }
        public Document()
        {
        }

        public Document(string title, string content)
        {
            this.Title = title;
            this.Content = content;
        }
    }
}

文档管理类（DocumentManager）泛型默认值、约束

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ListFunction
{
    /// <summary>
    /// TDocument必须实现IDocument接口（泛型约束）
    /// </summary>
    /// <typeparam name="TDocument"></typeparam>
    public class DocumentManager<TDocument>
        where TDocument:IDocument
    {
        private readonly Queue<TDocument> documentQueue = new Queue<TDocument>();
        /// <summary>
        /// 添加一个文档到队列尾
        /// </summary>
        /// <param name="doc"></param>
        public void AddDocument(TDocument doc)
        {
            lock (this) //单线程(个人理解、无依据)
            {
                documentQueue.Enqueue(doc); //添加到结尾处
            }
        }

        /// <summary>
        /// 队列不为空返回true
        /// </summary>
        public bool IsDocumentAvailable
        {
            get { return documentQueue.Count > 0; }
        }

        /// <summary>
        /// 获取文档（泛型默认值）
        /// </summary>
        /// <returns></returns>
        public TDocument GetDocument()
        {
            TDocument doc = default(TDocument); //将泛型类型初始化为null或0
            lock (this)
            {
                doc = documentQueue.Dequeue();  //移除并返回位于 System.Collections.Generic.Queue<T> 开始处的对象。
            }
            return doc;
        }

        /// <summary>
        /// 显示所有文档标题
        /// </summary>
        public void DisplayAllDocument()
        {
            foreach (TDocument doc in documentQueue)
            {
                Console.WriteLine(((IDocument)doc).Title);
                Console.WriteLine(((IDocument)doc).Content);
            }
        }

    }
}

测试类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ListFunction
{
    class Program
    {
        static void Main(string[] args)
        {
            var dm = new DocumentManager<Document>();
            dm.AddDocument(new Document("Title A","Sample A"));
            dm.AddDocument(new Document("Title B", "Sample B"));

            dm.DisplayAllDocument();

            if (dm.IsDocumentAvailable)
            {
                Document d = dm.GetDocument();
                Console.WriteLine(d.Content);
            }
        }
    }
}