我需要一个可序列化 XML 的字典。实际上，我现在有两个完全不同的程序需要一个。看到 .NET 没有一个，我感到相当惊讶。我在别处问了这个问题，得到了讽刺的回答。我不明白为什么这是一个愚蠢的问题。
鉴于各种 .NET 功能对 XML 序列化的依赖程度，有人可以启发我，为什么没有可序列化 XML 的字典。希望您还可以解释为什么有些人认为这是一个愚蠢的问题。我想我一定遗漏了一些基本的东西，我希望你能填补这些空白。
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46872 次
8 回答
53
我知道这个问题之前已经回答过了，但是因为我有一个非常简洁的方法（代码）来使用 DataContractSerializer 类（由 WCF 使用，但可以而且应该在任何地方使用）进行 IDictionary 序列化，所以我忍不住在这里贡献它：
public static class SerializationExtensions
{
public static string Serialize<T>(this T obj)
{
var serializer = new DataContractSerializer(obj.GetType());
using (var writer = new StringWriter())
using (var stm = new XmlTextWriter(writer))
{
serializer.WriteObject(stm, obj);
return writer.ToString();
}
}
public static T Deserialize<T>(this string serialized)
{
var serializer = new DataContractSerializer(typeof(T));
using (var reader = new StringReader(serialized))
using (var stm = new XmlTextReader(reader))
{
return (T)serializer.ReadObject(stm);
}
}
}
这在 .NET 4 中完美运行，也应该在 .NET 3.5 中运行，尽管我还没有测试它。
更新：它在 .NET Compact Framework（甚至 Windows Phone 7 的 NETCF 3.7）中不起作用，因为它DataContractSerializer不受支持！
我将流式传输到字符串是因为它对我来说更方便，虽然我可以向 Stream 引入较低级别的序列化，然后用它来序列化到字符串，但我倾向于仅在需要时进行泛化（就像过早优化是邪恶的一样，所以它是过早的概括......）
用法很简单：
// dictionary to serialize to string
Dictionary<string, object> myDict = new Dictionary<string, object>();
// add items to the dictionary...
myDict.Add(...);
// serialization is straight-forward
string serialized = myDict.Serialize();
...
// deserialization is just as simple
Dictionary<string, object> myDictCopy =
serialized.Deserialize<Dictionary<string,object>>();
myDictCopy 将是 myDict 的逐字副本。
您还会注意到，提供的泛型方法将能够序列化任何类型（据我所知），因为它不限于 IDictionary 接口，它实际上可以是任何泛型类型 T。
希望它可以帮助那里的人！
于 2011-05-09T18:49:19.913 回答
15
XML 序列化的问题在于它不仅仅是创建字节流。它还涉及创建一个 XML 模式，该字节流将对其进行验证。XML Schema 中没有表示字典的好方法。您能做的最好的事情就是证明有一个唯一的密钥。
您始终可以创建自己的包装器，例如One Way to Serialize Dictionaries。
于 2009-07-14T10:39:53.793 回答
13
他们在 .NET 3.0 中添加了一个。如果可以，请添加对 System.Runtime.Serialization 的引用并查找 System.Xml.XmlDictionary、System.Xml.XmlDictionaryReader 和 System.Xml.XmlDictionaryWriter。
我同意它不是在一个特别容易发现的地方。
于 2009-07-14T10:42:53.977 回答
4
创建一个你自己的:-)，只读特性是额外的，但如果你需要一个字符串以外的键，那么这个类需要一些修改......
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();
}
}
}
}
于 2009-07-14T10:42:27.703 回答
4
使用 DataContractSerializer！请参阅下面的示例。
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;
}
}
}
上面的代码生成以下 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>
于 2009-09-09T06:02:02.540 回答
2
一个通用的帮助器，可以在不使用继承的情况下快速将 IXmlSerializable 添加到任何（现有）字典：
using System.Xml;
using System.Xml.Serialization;
using System.Collections.Generic;
namespace GameSpace {
public class XmlSerializerForDictionary {
public struct Pair<TKey,TValue> {
public TKey Key;
public TValue Value;
public Pair(KeyValuePair<TKey,TValue> pair) {
Key = pair.Key;
Value = pair.Value;
}//method
}//struct
public static void WriteXml<TKey,TValue>(XmlWriter writer, IDictionary<TKey,TValue> dict) {
var list = new List<Pair<TKey,TValue>>(dict.Count);
foreach (var pair in dict) {
list.Add(new Pair<TKey,TValue>(pair));
}//foreach
var serializer = new XmlSerializer(list.GetType());
serializer.Serialize(writer, list);
}//method
public static void ReadXml<TKey, TValue>(XmlReader reader, IDictionary<TKey, TValue> dict) {
reader.Read();
var serializer = new XmlSerializer(typeof(List<Pair<TKey,TValue>>));
var list = (List<Pair<TKey,TValue>>)serializer.Deserialize(reader);
foreach (var pair in list) {
dict.Add(pair.Key, pair.Value);
}//foreach
reader.Read();
}//method
}//class
}//namespace
还有一个方便的可序列化通用字典：
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using System.Collections.Generic;
namespace GameSpace {
public class SerializableDictionary<TKey,TValue> : Dictionary<TKey,TValue>, IXmlSerializable {
public virtual void WriteXml(XmlWriter writer) {
XmlSerializerForDictionary.WriteXml(writer, this);
}//method
public virtual void ReadXml(XmlReader reader) {
XmlSerializerForDictionary.ReadXml(reader, this);
}//method
public virtual XmlSchema GetSchema() {
return null;
}//method
}//class
}//namespace
于 2012-05-07T12:07:52.437 回答
1
这是我的实现。
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml.Serialization;
using System.Xml.Schema;
using System.Xml;
namespace Rubik.Staging
{
[XmlSchemaProvider("GetInternalSchema")]
public class SerializableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IXmlSerializable
{
#region IXmlSerializable Members
private const string ns = "http://www.rubik.com.tr/staging";
public static XmlQualifiedName GetInternalSchema(XmlSchemaSet xs)
{
bool keyIsSimple = (typeof(TKey).IsPrimitive || typeof(TKey) == typeof(string));
bool valueIsSimple = (typeof(TValue).IsPrimitive || typeof(TValue) == typeof(string));
XmlSchemas schemas = new XmlSchemas();
XmlReflectionImporter importer = new XmlReflectionImporter(ns);
importer.IncludeType(typeof(TKey));
importer.IncludeType(typeof(TValue));
XmlTypeMapping keyMapping = importer.ImportTypeMapping(typeof(TKey));
XmlTypeMapping valueMapping = importer.ImportTypeMapping(typeof(TValue));
XmlSchemaExporter exporter = new XmlSchemaExporter(schemas);
if(!keyIsSimple)
exporter.ExportTypeMapping(keyMapping);
if(!valueIsSimple)
exporter.ExportTypeMapping(valueMapping);
XmlSchema schema = (schemas.Count == 0 ? new XmlSchema() : schemas[0]);
schema.TargetNamespace = ns;
XmlSchemaComplexType type = new XmlSchemaComplexType();
type.Name = "DictionaryOf" + keyMapping.XsdTypeName + "And" + valueMapping.XsdTypeName;
XmlSchemaSequence sequence = new XmlSchemaSequence();
XmlSchemaElement item = new XmlSchemaElement();
item.Name = "Item";
XmlSchemaComplexType itemType = new XmlSchemaComplexType();
XmlSchemaSequence itemSequence = new XmlSchemaSequence();
XmlSchemaElement keyElement = new XmlSchemaElement();
keyElement.Name = "Key";
keyElement.MaxOccurs = 1;
keyElement.MinOccurs = 1;
XmlSchemaComplexType keyType = new XmlSchemaComplexType();
XmlSchemaSequence keySequence = new XmlSchemaSequence();
XmlSchemaElement keyValueElement = new XmlSchemaElement();
keyValueElement.Name = keyMapping.ElementName;
keyValueElement.SchemaTypeName = new XmlQualifiedName(keyMapping.XsdTypeName, keyMapping.XsdTypeNamespace);
keyValueElement.MinOccurs = 1;
keyValueElement.MaxOccurs = 1;
keySequence.Items.Add(keyValueElement);
keyType.Particle = keySequence;
keyElement.SchemaType = keyType;
itemSequence.Items.Add(keyElement);
XmlSchemaElement valueElement = new XmlSchemaElement();
valueElement.Name = "Value";
valueElement.MaxOccurs = 1;
valueElement.MinOccurs = 1;
XmlSchemaComplexType valueType = new XmlSchemaComplexType();
XmlSchemaSequence valueSequence = new XmlSchemaSequence();
XmlSchemaElement valueValueElement = new XmlSchemaElement();
valueValueElement.Name = valueMapping.ElementName;
valueValueElement.SchemaTypeName = new XmlQualifiedName(valueMapping.XsdTypeName, valueMapping.XsdTypeNamespace);
valueValueElement.MinOccurs = 1;
valueValueElement.MaxOccurs = 1;
valueSequence.Items.Add(valueValueElement);
valueType.Particle = valueSequence;
valueElement.SchemaType = valueType;
itemSequence.Items.Add(valueElement);
itemType.Particle = itemSequence;
item.SchemaType = itemType;
sequence.Items.Add(item);
type.Particle = sequence;
schema.Items.Add(type);
xs.XmlResolver = new XmlUrlResolver();
xs.Add(schema);
return new XmlQualifiedName(type.Name, ns);
}
public void ReadXml(System.Xml.XmlReader reader)
{
XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));
bool wasEmpty = reader.IsEmptyElement;
reader.Read();
if (wasEmpty)
return;
while (reader.NodeType != System.Xml.XmlNodeType.EndElement)
{
reader.ReadStartElement("Item");
reader.ReadStartElement("Key");
TKey key = (TKey)keySerializer.Deserialize(reader);
reader.ReadEndElement();
reader.ReadStartElement("Value");
TValue value = (TValue)valueSerializer.Deserialize(reader);
reader.ReadEndElement();
this.Add(key, value);
reader.ReadEndElement();
reader.MoveToContent();
}
reader.ReadEndElement();
}
public void WriteXml(System.Xml.XmlWriter writer)
{
XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));
foreach (TKey key in this.Keys)
{
writer.WriteStartElement("Item");
writer.WriteStartElement("Key");
keySerializer.Serialize(writer, key);
writer.WriteEndElement();
writer.WriteStartElement("Value");
TValue value = this[key];
valueSerializer.Serialize(writer, value);
writer.WriteEndElement();
writer.WriteEndElement();
}
}
#endregion
#region IXmlSerializable Members
public XmlSchema GetSchema()
{
return null;
}
#endregion
}
}
于 2011-02-21T23:31:48.427 回答
1
我知道这已经被做死了，但这是我的贡献。我从@Loudenvier 和@Jack 的解决方案中吸取了精华，并编写了我自己的可序列化（对不起，我是英国人）字典类。
public class SerialisableDictionary<T1, T2> : Dictionary<T1, T2>, IXmlSerializable
{
private static DataContractSerializer serializer =
new DataContractSerializer(typeof(Dictionary<T1, T2>));
public void WriteXml(XmlWriter writer)
{
serializer.WriteObject(writer, this);
}
public void ReadXml(XmlReader reader)
{
Dictionary<T1, T2> deserialised =
(Dictionary<T1, T2>)serializer.ReadObject(reader);
foreach(KeyValuePair<T1, T2> kvp in deserialised)
{
Add(kvp.Key, kvp.Value);
}
}
public XmlSchema GetSchema()
{
return null;
}
}
我喜欢这种方法，因为您不必显式序列化或反序列化任何内容，只需通过 XmlSerializer 泵送整个类层次结构即可。
于 2015-12-08T10:42:26.597 回答