以下测试仅通过使用new XmlTextWriter(sw)代替XmlWriter.Create(sw, settings) or XmlTextWriter.Create(sw)：
public void ShouldGenerateRssFeed()
{
//reference: [http://dotnetslackers.com/articles/aspnet/How-to-create-a-syndication-feed-for-your-website.aspx]
var items = new List<SyndicationItem>
{
new SyndicationItem
{
Content = TextSyndicationContent.CreatePlaintextContent("This is plain test content for first item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for first item…"),
Title = TextSyndicationContent.CreatePlaintextContent("First Item Title")
},
new SyndicationItem
{
Content = TextSyndicationContent.CreatePlaintextContent("This is plain test content for second item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for second item…"),
Title = TextSyndicationContent.CreatePlaintextContent("Second Item Title")
},
new SyndicationItem
{
Content = TextSyndicationContent.CreateXhtmlContent("This is <strong>XHTML</strong> test content for <em>third</em> item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for third item…"),
Title = TextSyndicationContent.CreatePlaintextContent("Third Item Title")
}
};
var feed = new SyndicationFeed(items);
Assert.IsTrue((new List<SyndicationItem>(feed.Items)).Count == 3, "The expected number of Syndication items is not here.");
feed.Items.ForEachInEnumerable(i =>
{
i.Authors.Add( new SyndicationPerson
{
Email = "rasx@songhaysystem.com",
Name = "Bryan Wilhite",
Uri = "http://SonghaySystem.com"
});
});
var formatter = new Rss20FeedFormatter(feed);
var settings = new XmlWriterSettings
{
Encoding = Encoding.UTF8,
Indent = true,
IndentChars = " "
};
var buffer = new StringBuilder();
var output = string.Empty;
using(var sw = new StringWriter(buffer))
{
var writer = new XmlTextWriter(sw); //XmlWriter.Create(sw, settings) or XmlTextWriter.Create(sw) fails here!
formatter.WriteTo(writer);
output = buffer.ToString();
TestContext.WriteLine(output);
}
Assert.IsTrue(!output.Equals(string.Empty), "The expected output is not here.");
}
顺便说一下，我在上面的示例中使用了扩展方法ForEachInEnumerable：
/// <summary>
/// Extensions for <see cref="System.Collections.Generic.IEnumerable<T>"/>.
/// </summary>
public static class IEnumerableOfTExtensions
{
/// <summary>
/// Performs the <see cref="System.Action"/>
/// on each item in the enumerable object.
/// </summary>
/// <typeparam name="TEnumerable">The type of the enumerable.</typeparam>
/// <param name="enumerable">The enumerable.</param>
/// <param name="action">The action.</param>
/// <remarks>
/// “I am philosophically opposed to providing such a method, for two reasons.
/// …The first reason is that doing so violates the functional programming principles
/// that all the other sequence operators are based upon. Clearly the sole purpose of a call
/// to this method is to cause side effects.”
/// —Eric Lippert, “foreach” vs “ForEach” [http://blogs.msdn.com/b/ericlippert/archive/2009/05/18/foreach-vs-foreach.aspx]
/// </remarks>
public static void ForEachInEnumerable<TEnumerable>(this IEnumerable<TEnumerable> enumerable, Action<TEnumerable> action)
{
foreach(var item in enumerable)
{
action(item);
}
}
}
答案 0 :(得分：2)
我using错误的Disposable对象：StringBuilder不需要StringWriter ---我没有冲洗XmlWriter（这是一种做法，可以追溯到.NET 2.0）：
[TestMethod]
public void ShouldGenerateRssFeed()
{
//reference: [http://dotnetslackers.com/articles/aspnet/How-to-create-a-syndication-feed-for-your-website.aspx]
var items = new List<SyndicationItem>
{
new SyndicationItem
{
Content = TextSyndicationContent.CreatePlaintextContent("This is plain test content for first item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for first item…"),
Title = TextSyndicationContent.CreatePlaintextContent("First Item Title")
},
new SyndicationItem
{
Content = TextSyndicationContent.CreatePlaintextContent("This is plain test content for second item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for second item…"),
Title = TextSyndicationContent.CreatePlaintextContent("Second Item Title")
},
new SyndicationItem
{
Content = TextSyndicationContent.CreateXhtmlContent("This is <strong>XHTML</strong> test content for <em>third</em> item."),
PublishDate = DateTime.Now,
Summary = TextSyndicationContent.CreatePlaintextContent("Item summary for third item…"),
Title = TextSyndicationContent.CreatePlaintextContent("Third Item Title")
}
};
var feed = new SyndicationFeed(items)
{
Description = TextSyndicationContent.CreatePlaintextContent("My feed description."),
Title = TextSyndicationContent.CreatePlaintextContent("My Feed")
};
feed.Authors.Add(new SyndicationPerson
{
Email = "rasx@songhaysystem.com",
Name = "Bryan Wilhite",
Uri = "http://SonghaySystem.com"
});
Assert.IsTrue((new List<SyndicationItem>(feed.Items)).Count == 3, "The expected number of Syndication items is not here.");
feed.Items.ForEachInEnumerable(i =>
{
i.Authors.Add(feed.Authors.First());
});
var formatter = new Rss20FeedFormatter(feed);
var settings = new XmlWriterSettings
{
CheckCharacters = true,
CloseOutput = true,
ConformanceLevel = ConformanceLevel.Document,
Encoding = Encoding.UTF8,
Indent = true,
IndentChars = " ",
NamespaceHandling = NamespaceHandling.OmitDuplicates,
NewLineChars = "\r\n",
NewLineHandling = NewLineHandling.Replace,
NewLineOnAttributes = true,
OmitXmlDeclaration = false
};
var buffer = new StringBuilder();
var output = string.Empty;
using(var writer = XmlWriter.Create(buffer, settings))
{
formatter.WriteTo(writer); // or feed.SaveAsRss20(writer);
writer.Flush();
writer.Close();
output = buffer.ToString();
}
TestContext.WriteLine(output);
Assert.IsTrue(!output.Equals(string.Empty), "The expected output is not here.");
}