反序列化 XML 元素返回 NULL

Question

I am trying to deserialize an XML file. However, I only want two elements from the file. Here's the basic markup:

<Stuff>
  <Details>
    <Comment>I want whats in here.</Comment>
    <LogLevel>And here too.</LogLevel>
  </Details>
<Stuff>

To deserialize I'm doing the following:

XmlSerializer deserializer;
FileStream stream = new FileStream(CONFIG_PATH, FileMode.Open);
XmlReader reader = new XmlTextReader(stream);

XmlRootAttribute xRoot = new XmlRootAttribute();
xRoot.ElementName = "Stuff";
xRoot.IsNullable = true;

// Details configuration area.
Utilities.Details d = new Utilities.Details();
deserializer = new XmlSerializer((typeof(Details)), xRoot);
d = (Details)deserializer.Deserialize(reader);

System.Windows.MessageBox.Show(d.Comment);

And finally the class that holds the objects:

/// <summary>
/// Configuration details.
/// </summary>
[Serializable()]
[XmlRoot(ElementName = "Details", IsNullable = true)]
public sealed class Details
{
    public Details()
    {

    }

    [XmlElement("Comment")]
    public string Comment { get; set; }

    [XmlElement("LogLevel")]
    public string LogLevel { get; set; }
}

However d.Comment and d.LogLevel continue to return null no matter what I do. Any ideas?

Answer 1

With that setup, it expects

<Stuff>
  <Comment>....
  <LogLevel>...
  ...

To handle two levels in the XML you will need an object model that matches. Rather than messing with the XmlRootAttribute at runtime, write a type Stuff that has a Details instance in a property called Details. Then create the serializer to expect a Stuff instance:

public class Stuff {
    public Details Details {get;set;}
}

An alternative approach would be to use a sub-reader over the input, but that is harder.

Answer 2

I ran into a lot of similar issues when I was attempting to use XmlSerializer and FileStreams.

I would suggest changing this to Linq to XML. I found it to be a lot easier and faster to learn.

Here is a great Video by Mike Taulty

Linq to XML Tutorial