HOW TO：建立基本 Atom 摘要

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02/28/2011

Windows Communication Foundation (WCF) 可以讓您建立公開新聞訂閱摘要的服務。本主題討論如何建立可公開 Atom 新聞訂閱摘要的新聞訂閱服務。

若要建立基本新聞訂閱服務

使用以 WebGetAttribute 屬性標記的介面來定義服務合約。每個公開為新聞訂閱摘要的作業都應該傳回 Atom10FeedFormatter 物件。

[ServiceContract]
public interface IBlog
{
    [OperationContract]
    [WebGet]
    Atom10FeedFormatter GetBlog();
}

注意：
所有套用 WebGetAttribute 的服務作業都會對應至 HTTP GET 要求。若要將您的作業對應至不同的 HTTP 方法，請改用 WebInvokeAttribute。如需詳細資訊，請參閱 HOW TO：建立基本 WCF Web HTTP 服務.

實作服務合約。

public class BlogService : IBlog
{
    public Atom10FeedFormatter GetBlog()
    {
        SyndicationFeed feed = new SyndicationFeed("My Blog Feed", "This is a test feed", new Uri("http://SomeURI"), "FeedOneID", new DateTimeOffset(DateTime.Now));
        feed.Authors.Add(new SyndicationPerson("someone@microsoft.com"));
        feed.Categories.Add(new SyndicationCategory("How To Sample Code"));
        feed.Description = new TextSyndicationContent("This is a sample that illistrates how to expose a feed using ATOM with WCF");

        SyndicationItem item1 = new SyndicationItem(
            "Item One",
            "This is the content for item one",
            new Uri("https://localhost/Content/One"),
            "ItemOneID",
            DateTime.Now);

        SyndicationItem item2 = new SyndicationItem(
            "Item Two",
            "This is the content for item two",
            new Uri("https://localhost/Content/Two"),
            "ItemTwoID",
            DateTime.Now);

        SyndicationItem item3 = new SyndicationItem(
            "Item Three",
            "This is the content for item three",
            new Uri("https://localhost/Content/three"),
            "ItemThreeID",
            DateTime.Now);
        List<SyndicationItem> items = new List<SyndicationItem>();

        items.Add(item1);
        items.Add(item2);
        items.Add(item3);

        feed.Items = items;
        return new Atom10FeedFormatter(feed);
    }
}

建立 SyndicationFeed 物件並加入作者、分類和描述。

SyndicationFeed feed = new SyndicationFeed("My Blog Feed", "This is a test feed", new Uri("http://SomeURI"), "FeedOneID", new DateTimeOffset(DateTime.Now));
feed.Authors.Add(new SyndicationPerson("someone@microsoft.com"));
feed.Categories.Add(new SyndicationCategory("How To Sample Code"));
feed.Description = new TextSyndicationContent("This is a sample that illistrates how to expose a feed using ATOM with WCF");

建立幾個 SyndicationItem 物件。

SyndicationItem item1 = new SyndicationItem(
    "Item One",
    "This is the content for item one",
    new Uri("https://localhost/Content/One"),
    "ItemOneID",
    DateTime.Now);

SyndicationItem item2 = new SyndicationItem(
    "Item Two",
    "This is the content for item two",
    new Uri("https://localhost/Content/Two"),
    "ItemTwoID",
    DateTime.Now);

SyndicationItem item3 = new SyndicationItem(
    "Item Three",
    "This is the content for item three",
    new Uri("https://localhost/Content/three"),
    "ItemThreeID",
    DateTime.Now);

新增 SyndicationItem 物件至摘要。

List<SyndicationItem> items = new List<SyndicationItem>();

items.Add(item1);
items.Add(item2);
items.Add(item3);

feed.Items = items;

傳回摘要。
```
return new Atom10FeedFormatter(feed);
```

若要裝載服務

建立 WebServiceHost 物件。

Uri baseAddress = new Uri("https://localhost:8000/BlogService/");
WebServiceHost svcHost = new WebServiceHost(typeof(BlogService), baseAddress);

開啟服務主機、從服務載入摘要、顯示摘要，並等候使用者按下 ENTER。

svcHost.Open();
Console.WriteLine("Service is running");

XmlReader reader = XmlReader.Create("https://localhost:8000/BlogService/GetBlog");
SyndicationFeed feed = SyndicationFeed.Load(reader);
Console.WriteLine(feed.Title.Text);
Console.WriteLine("Items:");
foreach (SyndicationItem item in feed.Items)
{
    Console.WriteLine("Title: {0}", item.Title.Text);
    Console.WriteLine("Content: {0}", ((TextSyndicationContent)item.Content).Text);
}
Console.WriteLine("Press <ENTER> to quit...");
Console.ReadLine();
svcHost.Close();

若要使用 HTTP GET 呼叫 GetBlog()

開啟 Internet Explorer 並輸入下列 URL，然後按下 ENTER：https://localhost:8000/BlogService/GetBlog

URL 包含服務的基底位址 (https://localhost:8000/BlogService)、端點的相對位址，以及要呼叫的服務作業。

若要從程式碼呼叫 GetBlog()

使用基底位址與您要呼叫的方法建立 XmlReader。

XmlReader reader = XmlReader.Create("https://localhost:8000/BlogService/GetBlog");

呼叫靜態 Load 方法，傳入剛才建立的 XmlReader。
```
SyndicationFeed feed = SyndicationFeed.Load(reader);
```
這會叫用服務作業，並在新的 SyndicationFeed 中填入服務作業所傳回的格式器。

存取摘要物件。

Console.WriteLine(feed.Title.Text);
Console.WriteLine("Items:");
foreach (SyndicationItem item in feed.Items)
{
    Console.WriteLine("Title: {0}", item.Title.Text);
    Console.WriteLine("Summary: {0}", ((TextSyndicationContent)item.Summary).Text);
}

範例

以下是這個範例的完整程式碼清單。

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ServiceModel;
using System.Xml;
using System.ServiceModel.Description;
using System.ServiceModel.Syndication;
using System.ServiceModel.Channels;
using System.ServiceModel.Web;

namespace Service
{
    [ServiceContract]
    public interface IBlog
    {
        [OperationContract]
        [WebGet]
        Atom10FeedFormatter GetBlog();
    }

    public class BlogService : IBlog
    {
        public Atom10FeedFormatter GetBlog()
        {
            SyndicationFeed feed = new SyndicationFeed("My Blog Feed", "This is a test feed", new Uri("http://SomeURI"), "FeedOneID", new DateTimeOffset(DateTime.Now));
            feed.Authors.Add(new SyndicationPerson("someone@microsoft.com"));
            feed.Categories.Add(new SyndicationCategory("How To Sample Code"));
            feed.Description = new TextSyndicationContent("This is a sample that illistrates how to expose a feed using ATOM with WCF");

            SyndicationItem item1 = new SyndicationItem(
                "Item One",
                "This is the content for item one",
                new Uri("https://localhost/Content/One"),
                "ItemOneID",
                DateTime.Now);

            SyndicationItem item2 = new SyndicationItem(
                "Item Two",
                "This is the content for item two",
                new Uri("https://localhost/Content/Two"),
                "ItemTwoID",
                DateTime.Now);

            SyndicationItem item3 = new SyndicationItem(
                "Item Three",
                "This is the content for item three",
                new Uri("https://localhost/Content/three"),
                "ItemThreeID",
                DateTime.Now);
            List<SyndicationItem> items = new List<SyndicationItem>();

            items.Add(item1);
            items.Add(item2);
            items.Add(item3);

            feed.Items = items;
            return new Atom10FeedFormatter(feed);
        }
    }

    public class Host
    {
        static void Main(string[] args)
        {
            Uri baseAddress = new Uri("https://localhost:8000/BlogService/");
            WebServiceHost svcHost = new WebServiceHost(typeof(BlogService), baseAddress);
            try
            {
                svcHost.Open();
                Console.WriteLine("Service is running");

                XmlReader reader = XmlReader.Create("https://localhost:8000/BlogService/GetBlog");
                SyndicationFeed feed = SyndicationFeed.Load(reader);
                Console.WriteLine(feed.Title.Text);
                Console.WriteLine("Items:");
                foreach (SyndicationItem item in feed.Items)
                {
                    Console.WriteLine("Title: {0}", item.Title.Text);
                    Console.WriteLine("Content: {0}", ((TextSyndicationContent)item.Content).Text);
                }
                Console.WriteLine("Press <ENTER> to quit...");
                Console.ReadLine();
                svcHost.Close();
            }
            catch (CommunicationException ce)
            {
                Console.WriteLine("An exception occurred: {0}", ce.Message);
                svcHost.Abort();
            }
        }
    }
}

編譯程式碼

在編譯先前的程式碼時，請參考 System.ServiceModel.dll 和 System.ServiceModel.Web.dll。

另請參閱

參考

WebHttpBinding
WebGetAttribute

共用方式為