Почему не там XML-сериализуемый словарь в.NET?
Посмотрите, помогает ли это:
[Serializable()]
[System.Xml.Serialization.XmlRootAttribute("Cars", Namespace = "", IsNullable = false)]
public class Cars
{
[XmlArrayItem(typeof(Car))]
public Car[] Car { get; set; }
}
.
[Serializable()]
public class Car
{
[System.Xml.Serialization.XmlElement()]
public string StockNumber{ get; set; }
[System.Xml.Serialization.XmlElement()]
public string Make{ get; set; }
[System.Xml.Serialization.XmlElement()]
public string Model{ get; set; }
}
И сбой, которые используют программу xsd.exe, которая идет с Visual Studio, чтобы создать документ схемы на основе этого xml файл, и затем использовать его снова для создания класса на основе документа схемы.
4 ответа
The thing about XML Serialization is that it's not just about creating a stream of bytes. It's also about creating an XML Schema that this stream of bytes would validate against. There's no good way in XML Schema to represent a dictionary. The best you could do is to show that there's a unique key.
You can always create your own wrapper, for instance One Way to Serialize Dictionaries.
They added one in .NET 3.0. If you can, add a reference to System.Runtime.Serialization and look for System.Xml.XmlDictionary, System.Xml.XmlDictionaryReader, and System.Xml.XmlDictionaryWriter.
I would agree that it is not in a particularly discoverable place.
Create one of your own :-), the readonly feature is bonus but if you need a key other than a string then the class needs some modifications...
namespace MyNameSpace
{
[XmlRoot("SerializableDictionary")]
public class SerializableDictionary : Dictionary<String, Object>, IXmlSerializable
{
internal Boolean _ReadOnly = false;
public Boolean ReadOnly
{
get
{
return this._ReadOnly;
}
set
{
this.CheckReadOnly();
this._ReadOnly = value;
}
}
public new Object this[String key]
{
get
{
Object value;
return this.TryGetValue(key, out value) ? value : null;
}
set
{
this.CheckReadOnly();
if(value != null)
{
base[key] = value;
}
else
{
this.Remove(key);
}
}
}
internal void CheckReadOnly()
{
if(this._ReadOnly)
{
throw new Exception("Collection is read only");
}
}
public new void Clear()
{
this.CheckReadOnly();
base.Clear();
}
public new void Add(String key, Object value)
{
this.CheckReadOnly();
base.Add(key, value);
}
public new void Remove(String key)
{
this.CheckReadOnly();
base.Remove(key);
}
public XmlSchema GetSchema()
{
return null;
}
public void ReadXml(XmlReader reader)
{
Boolean wasEmpty = reader.IsEmptyElement;
reader.Read();
if(wasEmpty)
{
return;
}
while(reader.NodeType != XmlNodeType.EndElement)
{
if(reader.Name == "Item")
{
String key = reader.GetAttribute("Key");
Type type = Type.GetType(reader.GetAttribute("TypeName"));
reader.Read();
if(type != null)
{
this.Add(key, new XmlSerializer(type).Deserialize(reader));
}
else
{
reader.Skip();
}
reader.ReadEndElement();
reader.MoveToContent();
}
else
{
reader.ReadToFollowing("Item");
}
reader.ReadEndElement();
}
public void WriteXml(XmlWriter writer)
{
foreach(KeyValuePair<String, Object> item in this)
{
writer.WriteStartElement("Item");
writer.WriteAttributeString("Key", item.Key);
writer.WriteAttributeString("TypeName", item.Value.GetType().AssemblyQualifiedName);
new XmlSerializer(item.Value.GetType()).Serialize(writer, item.Value);
writer.WriteEndElement();
}
}
}
}
Используйте DataContractSerializer! См. Пример ниже.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization;
using System.Xml;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
A a = new A();
a.Value = 1;
B b = new B();
b.Value = "SomeValue";
Dictionary<A, B> d = new Dictionary<A,B>();
d.Add(a, b);
DataContractSerializer dcs = new DataContractSerializer(typeof(Dictionary<A, B>));
StringBuilder sb = new StringBuilder();
using (XmlWriter xw = XmlWriter.Create(sb))
{
dcs.WriteObject(xw, d);
}
string xml = sb.ToString();
}
}
public class A
{
public int Value
{
get;
set;
}
}
public class B
{
public string Value
{
get;
set;
}
}
}
Приведенный выше код создает следующий xml:
<?xml version="1.0" encoding="utf-16"?>
<ArrayOfKeyValueOfABHtQdUIlS xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
<KeyValueOfABHtQdUIlS>
<Key xmlns:d3p1="http://schemas.datacontract.org/2004/07/ConsoleApplication1">
<d3p1:Value>1</d3p1:Value>
</Key>
<Value xmlns:d3p1="http://schemas.datacontract.org/2004/07/ConsoleApplication1">
<d3p1:Value>SomeValue</d3p1:Value>
</Value>
</KeyValueOfABHtQdUIlS>
</ArrayOfKeyValueOfABHtQdUIlS>