Instrukcje: tworzenie podstawowego kanału informacyjnego Atom

2025-03-29

Program Windows Communication Foundation (WCF) umożliwia utworzenie usługi, która udostępnia kanał informacyjny. W tym temacie omówiono sposób tworzenia usługi syndykacji, która udostępnia kanał syndykacji Atom.

Aby utworzyć podstawową usługę syndykacji

Zdefiniuj kontrakt usługi przy użyciu interfejsu oznaczonego atrybutem WebGetAttribute. Każda operacja uwidoczniona jako źródło danych syndykacji powinna zwrócić obiekt Atom10FeedFormatter.
```
[ServiceContract]
public interface IBlog
{
    [OperationContract]
    [WebGet]
    Atom10FeedFormatter GetBlog();
}
```
```
<ServiceContract()> _
Public Interface IBlog
    <OperationContract()> _
    <WebGet> _
    Function GetBlog() As Atom10FeedFormatter
End Interface
```
Uwaga

Wszystkie operacje usługi, które stosują WebGetAttribute, są mapowane na żądania HTTP GET. Aby zamapować operację na inną metodę HTTP, użyj WebInvokeAttribute zamiast tego. Aby uzyskać więcej informacji, zobacz How to: Create a Basic WCF Web HTTP Service.

Zaimplementuj kontrakt usługi.

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 illustrates how to expose a feed using ATOM with WCF");

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

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

        SyndicationItem item3 = new SyndicationItem(
            "Item Three",
            "This is the content for item three",
            new Uri("http://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 BlogService
    Implements IBlog
    Public Function GetBlog() As Atom10FeedFormatter Implements IBlog.GetBlog
        Dim feed As 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 illustrates how to expose a feed imports ATOM with WCF")

        Dim item1 As New SyndicationItem( _
            "Item One", _
            "This is the content for item one", _
            New Uri("http://localhost/Content/One"), _
            "ItemOneID", _
            DateTime.Now)

        Dim item2 As New SyndicationItem( _
            "Item Two", _
            "This is the content for item two", _
            New Uri("http://localhost/Content/Two"), _
            "ItemTwoID", _
            DateTime.Now)

        Dim item3 As New SyndicationItem( _
            "Item Three", _
            "This is the content for item three", _
            New Uri("http://localhost/Content/three"), _
            "ItemThreeID", _
            DateTime.Now)
        Dim items As New List(Of SyndicationItem)()

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

        feed.Items = items
        Return New Atom10FeedFormatter(feed)
    End Function
End Class

Utwórz obiekt SyndicationFeed i dodaj autora, kategorię i opis.

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 illustrates how to expose a feed using ATOM with WCF");

Dim feed As 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 illustrates how to expose a feed imports ATOM with WCF")

Utwórz kilka obiektów SyndicationItem.

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

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

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

Dim item1 As New SyndicationItem( _
    "Item One", _
    "This is the content for item one", _
    New Uri("http://localhost/Content/One"), _
    "ItemOneID", _
    DateTime.Now)

Dim item2 As New SyndicationItem( _
    "Item Two", _
    "This is the content for item two", _
    New Uri("http://localhost/Content/Two"), _
    "ItemTwoID", _
    DateTime.Now)

Dim item3 As New SyndicationItem( _
    "Item Three", _
    "This is the content for item three", _
    New Uri("http://localhost/Content/three"), _
    "ItemThreeID", _
    DateTime.Now)

Dodaj obiekty SyndicationItem do kanału.

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

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

feed.Items = items;

Dim items As New List(Of SyndicationItem)()

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

feed.Items = items

Zwróć kanał.

return new Atom10FeedFormatter(feed);

Return New Atom10FeedFormatter(feed)

Aby gospodarować usługą

Utwórz obiekt WebServiceHost.

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

Dim baseAddress As New Uri("http://localhost:8000/BlogService/")
Dim svcHost As New WebServiceHost(GetType(BlogService), baseAddress)

Otwórz hosta usługi, załaduj źródło danych z usługi, wyświetl źródło danych i poczekaj, aż użytkownik naciśnie ENTER.

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

XmlReader reader = XmlReader.Create("http://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($"Title: {item.Title.Text}");
    Console.WriteLine($"Content: {((TextSyndicationContent)item.Content).Text}");
}
Console.WriteLine("Press <ENTER> to quit...");
Console.ReadLine();
svcHost.Close();

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

Dim reader As XmlReader = XmlReader.Create("http://localhost:8000/BlogService/GetBlog")
Dim feed As SyndicationFeed = SyndicationFeed.Load(reader)
Console.WriteLine(feed.Title.Text)
Console.WriteLine("Items:")

For Each item As SyndicationItem In feed.Items
    Console.WriteLine("Title: {0}", item.Title.Text)
    Console.WriteLine("Content: {0}", item.Title.Text)
Next

Console.WriteLine("Press <ENTER> to quit...")
Console.ReadLine()
svcHost.Close()

Aby wywołać metodę GetBlog() przy użyciu metody HTTP GET

W przeglądarce internetowej przejdź do następującego adresu URL: http://localhost:8000/BlogService/GetBlog

Adres URL zawiera podstawowy adres usługi (http://localhost:8000/BlogService), względny adres punktu końcowego i operację usługi do wywołania.

Aby wywołać metodę GetBlog() z kodu

Utwórz XmlReader z użyciem adresu bazowego oraz metody, którą wywołujesz.

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

Dim serviceAddress As New Uri("http://localhost:8000/BlogService/GetBlog")

Wywołaj metodę statyczną Load(XmlReader), przekazując XmlReader, którą właśnie utworzyłeś.
```
SyndicationFeed feed = SyndicationFeed.Load(reader);
```
```
Dim feed As SyndicationFeed = SyndicationFeed.Load(serviceAddress)
```
Powoduje to wywołanie operacji usługi i wypełnienie nowego SyndicationFeed formatyzerem zwróconym z operacji usługi.

Uzyskaj dostęp do obiektu kanału informacyjnego.

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

Console.WriteLine(feed.Title.Text)
Console.WriteLine("Items:")
For Each item As SyndicationItem In feed.Items
    Console.WriteLine("Title: {0}", item.Title.Text)
    Console.WriteLine("Summary: {0}", item.Summary.Text)
Next

Przykład

Poniżej znajduje się pełna lista kodu dla tego przykładu.

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 illustrates how to expose a feed using ATOM with WCF");

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

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

            SyndicationItem item3 = new SyndicationItem(
                "Item Three",
                "This is the content for item three",
                new Uri("http://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("http://localhost:8000/BlogService/");
            WebServiceHost svcHost = new WebServiceHost(typeof(BlogService), baseAddress);
            try
            {
                svcHost.Open();
                Console.WriteLine("Service is running");

                XmlReader reader = XmlReader.Create("http://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($"Title: {item.Title.Text}");
                    Console.WriteLine($"Content: {((TextSyndicationContent)item.Content).Text}");
                }
                Console.WriteLine("Press <ENTER> to quit...");
                Console.ReadLine();
                svcHost.Close();
            }
            catch (CommunicationException ce)
            {
                Console.WriteLine($"An exception occurred: {ce.Message}");
                svcHost.Abort();
            }
        }
    }
}

Imports System.Xml
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Imports System.ServiceModel
Imports System.ServiceModel.Description
Imports System.ServiceModel.Syndication
Imports System.ServiceModel.Channels
Imports System.ServiceModel.Web

<ServiceContract()> _
Public Interface IBlog
    <OperationContract()> _
    <WebGet> _
    Function GetBlog() As Atom10FeedFormatter
End Interface

Public Class BlogService
    Implements IBlog
    Public Function GetBlog() As Atom10FeedFormatter Implements IBlog.GetBlog
        Dim feed As 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 illustrates how to expose a feed imports ATOM with WCF")

        Dim item1 As New SyndicationItem( _
            "Item One", _
            "This is the content for item one", _
            New Uri("http://localhost/Content/One"), _
            "ItemOneID", _
            DateTime.Now)

        Dim item2 As New SyndicationItem( _
            "Item Two", _
            "This is the content for item two", _
            New Uri("http://localhost/Content/Two"), _
            "ItemTwoID", _
            DateTime.Now)

        Dim item3 As New SyndicationItem( _
            "Item Three", _
            "This is the content for item three", _
            New Uri("http://localhost/Content/three"), _
            "ItemThreeID", _
            DateTime.Now)
        Dim items As New List(Of SyndicationItem)()

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

        feed.Items = items
        Return New Atom10FeedFormatter(feed)
    End Function
End Class

Module Program

    Sub Main()
        Dim baseAddress As New Uri("http://localhost:8000/BlogService/")
        Dim svcHost As New WebServiceHost(GetType(BlogService), baseAddress)
        Try
            svcHost.AddServiceEndpoint(GetType(IBlog), New WebHttpBinding(), "")
            svcHost.Open()
            Console.WriteLine("Service is running")

            Dim reader As XmlReader = XmlReader.Create("http://localhost:8000/BlogService/GetBlog")
            Dim feed As SyndicationFeed = SyndicationFeed.Load(reader)
            Console.WriteLine(feed.Title.Text)
            Console.WriteLine("Items:")

            For Each item As SyndicationItem In feed.Items
                Console.WriteLine("Title: {0}", item.Title.Text)
                Console.WriteLine("Content: {0}", item.Title.Text)
            Next

            Console.WriteLine("Press <ENTER> to quit...")
            Console.ReadLine()
            svcHost.Close()

        Catch ce As CommunicationException
            Console.WriteLine("An exception occurred: {0}", ce.Message)
            svcHost.Abort()
        End Try
    End Sub

End Module

Kompilowanie kodu

Podczas kompilowania poprzedniego kodu należy odwołać się do System.ServiceModel.dll i System.ServiceModel.Web.dll.

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