如何使用XmlSerializer将简单集合反序列化为List 的实例

I haven't been able to find a question related to my specific problem.

我无法找到与我的具体问题相关的问题。

What I am trying to do is take a list of Xml nodes, and directly deserialize them to a List without having to create a class with attributes.

我要做的是获取Xml节点列表，并直接将它们反序列化为List，而不必创建具有属性的类。

So the xml (myconfig.xml) would look something like this...

所以xml（myconfig.xml）看起来像这样......

<collection>  
    <item>item1</item>
    <item>item2</item>
    <item>item3</item>
    <item>etc...</item>
</collection>

In the end I would like a list of items as strings.

最后，我想要一个项目列表作为字符串。

The code would look like this.

代码看起来像这样。

XmlSerializer serializer = new XmlSerializer( typeof( List<string> ) );
using (XmlReader reader = XmlReader.Create( "myconfig.xml" )
{
    List<string> itemCollection = (List<string>)serializer.Deserialize( reader );
}

I'm not 100% confident that this is possible, but I'm guessing it should be. Any help would be greatly appreciated.

我不是百分之百地确信这是可能的，但我猜它应该是。任何帮助将不胜感激。

3 个解决方案

#1

Are you married to the idea of using a serializer? If not, you can try Linq-to-XML. (.NET 3.5, C# 3 [and higher])

你嫁给了使用序列化器的想法吗？如果没有，您可以尝试Linq-to-XML。（.NET 3.5，C＃3 [及更高版本]）

Based on your provided XML file format, this is the simple code.

根据您提供的XML文件格式，这是简单的代码。

// add 'using System.Xml.Linq' to your code file
string file = @"C:\Temp\myconfig.xml";
XDocument document = XDocument.Load(file);
List<string> list = (from item in document.Root.Elements("item")
                     select item.Value)
                    .ToList();

#2

Ok, interestingly enough I may have found half the answer by serializing an existing List.

好的，有趣的是，通过序列化现有的List，我可能找到了一半的答案。

The result I got is as follows...

我得到的结果如下......

This following code:

以下代码：

List<string> things = new List<string> { "thing1", "thing2" };
XmlSerializer serializer = new XmlSerializer(typeof(List<string>), overrides);
using (TextWriter textWriter = new StreamWriter("things.xml"))
{
    serializer.Serialize(textWriter, things);
}

Outputs a result of:

输出结果：

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <string>thing1</string>
    <string>thing2</string>
</ArrayOfString>

I can override the root node by passing an XmlAttributeOverrides instance to the second parameter of the XmlSerializer constructor. It is created like this:

我可以通过将XmlAttributeOverrides实例传递给XmlSerializer构造函数的第二个参数来覆盖根节点。它是这样创建的：

XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attributes = new XmlAttributes { XmlRoot = new XmlRootAttribute("collection") };
overrides.Add( typeof(List<string>), attributes );

This will change "ArrayOfString" to "collection". I still have not figured out how to control the name of the string element.

这会将“ArrayOfString”更改为“collection”。我还没弄明白如何控制字符串元素的名称。

#3

To customize List element names using XmlSerializer, you have to wrap the list.

要使用XmlSerializer自定义List元素名称，必须包装列表。

[XmlRoot(Namespace="", ElementName="collection")]
public class ConfigWrapper
{
    [XmlElement("item")]
    public List<string> Items{ get; set;}
}

Usage:

用法：

   var itemsList = new List<string>{"item1", "item2", "item3"};
   var cfgIn = new ConfigWrapper{ Items = itemsList };
   var xs = new XmlSerializer(typeof(ConfigWrapper));
   string fileContent = null;

   using (var sw = new StringWriter())
   {
        xs.Serialize(sw, cfgIn);
        fileContent = sw.ToString();
        Console.WriteLine (fileContent);
   }

   ConfigWrapper cfgOut = null;
   using (var sr = new StringReader(fileContent))
   {
        cfgOut = xs.Deserialize(sr) as ConfigWrapper;
        // cfgOut.Dump(); //view in LinqPad
        if(cfgOut != null)
            // yields 'item2'
            Console.WriteLine (cfgOut.Items[1]);
   }

Output:

输出：

// fileContent:
<?xml version="1.0" encoding="utf-16"?>
<collection xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <item>item1</item>
  <item>item2</item>
  <item>item3</item>
</collection>

If you don't want to wrap the list, the DataContractSerializer will allow you to custom name the elements if you subclass it:

如果您不想包装列表，DataContractSerializer将允许您在子类化时自定义元素的名称：

[CollectionDataContract(Name = "collection", ItemName = "item", Namespace = "")]
public class ConfigWrapper : List<string>
{
    public ConfigWrapper() : base() { }
    public ConfigWrapper(IEnumerable<string> items) : base(items) { }
    public ConfigWrapper(int capacity) : base(capacity) { }
}

Usage And Output:

用法和输出：

   var cfgIn = new ConfigWrapper{ "item1", "item2", "item3" };
   var ds = new DataContractSerializer(typeof(ConfigWrapper));
   string fileContent = null;

   using (var ms = new MemoryStream())
   {
        ds.WriteObject(ms, cfgIn);
        fileContent = Encoding.UTF8.GetString(ms.ToArray());
        Console.WriteLine (fileContent);
   }
   // yields: <collection xmlns:i="http://www.w3.org/2001/XMLSchema-instance"><item>item1</item><item>item2</item><item>item3</item></collection>

   ConfigWrapper cfgOut = null;
   using (var sr = new StringReader(fileContent))
   {
        using(var xr = XmlReader.Create(sr))
        {
            cfgOut = ds.ReadObject(xr) as ConfigWrapper;
            // cfgOut.Dump(); //view in LinqPad
            if(cfgOut != null)
                // yields 'item2'
                Console.WriteLine (cfgOut[1]);
        }
   }

#1