更新:请看答案开始!这是我找到的最好的解决方案这是一个比这个更好的解决方案。
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深受csharptest.net评论的启发,我创建了一个类,它几乎完成了我想要的工作。:-)您可以通过检查ItemList.items来访问反序列化的项,并通过将项插入ItemList.items,然后使用适当的XmlSerializer对其进行序列化来对内容进行序列化。唯一有点麻烦的是,对于可能需要(反)序列化的每个类类型,必须确保ItemList类都使用XmlIncludeAttribute标记,否则XmlSerializer将无法处理它。
下面是示例程序,其中包含泛型ItemList类:
using System;
using System.IO;
using System.Text;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
namespace XmlTester
{
public class Program {
static void Main(string[] args) {
Console.WriteLine("XML tester...");
// Valid XML for an ItemList of Person's
XmlSerializer ser = new XmlSerializer(typeof(ItemList<Person>));
string xmlIn =
@"<ItemList xmlns:i=""http://www.w3.org/2001/XMLSchema-instance"">
<PersonBilingual>
<FullName>John Smith</FullName>
<Age>21</Age>
<Language>French</Language>
<SecondLanguage>German</SecondLanguage>
</PersonBilingual>
<Person>
<FullName>Joe Bloggs</FullName>
<Age>26</Age>
<Language>English</Language>
</Person>
<Person i:type=""PersonBilingual"">
<FullName>Jane Doe</FullName>
<Age>78</Age>
<Language>Italian</Language>
<SecondLanguage>English</SecondLanguage>
</Person>
</ItemList>";
//// Valid XML for an ItemList of Account's
//XmlSerializer ser = new XmlSerializer(typeof(ItemList<Account>));
//string xmlIn =
//@"<ItemList xmlns:i=""http://www.w3.org/2001/XMLSchema-instance"">
// <AccountBank>
// <AcctName>Deposit account</AcctName>
// <WithCompany>Bank of Switzerland</WithCompany>
// <BalanceInEuros>300</BalanceInEuros>
// </AccountBank>
// <Account>
// <AcctName>Book buying account</AcctName>
// <WithCompany>Amazon</WithCompany>
// </Account>
// <Account i:type=""AccountBank"">
// <AcctName>Savings account</AcctName>
// <WithCompany>Bank of America</WithCompany>
// <BalanceInEuros>2500</BalanceInEuros>
// </Account>
//</ItemList>";
//// Invalid XML, as we have mixed incompatible types
//XmlSerializer ser = new XmlSerializer(typeof(ItemList<Person>));
//string xmlIn =
//@"<ItemList xmlns:i=""http://www.w3.org/2001/XMLSchema-instance"">
// <PersonBilingual>
// <FullName>John Smith</FullName>
// <Age>21</Age>
// <Language>French</Language>
// <SecondLanguage>German</SecondLanguage>
// </PersonBilingual>
// <Account>
// <AcctName>Book buying account</AcctName>
// <WithCompany>Amazon</WithCompany>
// </Account>
// <Person i:type=""PersonBilingual"">
// <FullName>Jane Doe</FullName>
// <Age>78</Age>
// <Language>Italian</Language>
// <SecondLanguage>English</SecondLanguage>
// </Person>
//</ItemList>";
// Deserialize...
ItemList<Person> result;
using (var reader = new StringReader(xmlIn)) {
result = (ItemList<Person>)ser.Deserialize(reader);
}
Console.WriteLine("Break here and check 'result' in Quickwatch...");
Console.ReadKey();
// Serialize...
StringBuilder xmlOut = new StringBuilder();
ser.Serialize(new StringWriter(xmlOut), result);
Console.WriteLine("Break here and check 'xmlOut' in Quickwatch...");
Console.ReadKey();
}
}
[XmlRoot(ElementName = "ItemList", IsNullable = false)]
[XmlInclude(typeof(Person))]
[XmlInclude(typeof(PersonBilingual))]
[XmlInclude(typeof(Account))]
[XmlInclude(typeof(AccountBank))]
public class ItemList<T> : IXmlSerializable {
#region Private vars
/// <summary>
/// The class that will store our serializers for the various classes that may be (de)serialized, given
/// the type of this ItemList (ie. the type itself, as well as any type that extends the type)
/// </summary>
private class Map : Dictionary<string, XmlSerializer> { public Map() : base(StringComparer.Ordinal) { } }
#endregion
#region Private methods
/// <summary>
/// Creates a 'schema' for this ItemList, using its type, and the XmlIncludeAttribute types that are
/// associated with it. For each XmlIncludeAttribute, if it can be assigned to this ItemList's type (so
/// it's either the same type as this ItemList's type or a type that extends this ItemList's type), adds
/// the XmlSerializer for that XmlIncludeAttribute's type to our 'schema' collection, allowing a node
/// corresponding to that type to be (de)serialized by this ItemList.
/// </summary>
/// <returns>The 'schema' containing the XmlSerializer's available for this ItemList to use during (de)serialization.</returns>
private Map loadSchema() {
Map map = new Map();
foreach (XmlIncludeAttribute inc in typeof(ItemList<T>).GetCustomAttributes(typeof(XmlIncludeAttribute), true)) {
Type t = inc.Type;
if (typeof(T).IsAssignableFrom(t)) { map.Add(xmlTypeName(t), new XmlSerializer(t)); }
}
return map;
}
/// <summary>
/// As the XML type name can be different to our internal class name for that XML type, we need to be able
/// to expect an XML element name that is different to our internal class name for that XML type. Hence,
/// our 'schema' map will contain XmlSerializer's whose keys are based on the XML type name, NOT our
/// internal class name for that XML type. This method returns the XML type name given our internal
/// class we're using to (de)serialize that XML type. If no XML TypeName is specified in our internal
/// class's XmlTypeAttribute, we assume an XML type name identical to the internal class name.
/// </summary>
/// <param name="t">Our internal class used to (de)serialize an XML type.</param>
/// <returns>The XML type name corresponding to the given internal class.</returns>
private string xmlTypeName(Type t) {
string typeName = t.Name;
foreach (XmlTypeAttribute ta in t.GetCustomAttributes(typeof(XmlTypeAttribute), true)) {
if (!string.IsNullOrEmpty(ta.TypeName)) { typeName = ta.TypeName; }
}
return typeName;
}
#endregion
#region IXmlSerializable Members
/// <summary>
/// Reserved and should not be used.
/// </summary>
/// <returns>Must return null.</returns>
public XmlSchema GetSchema() {
return null;
}
/// <summary>
/// Generates a list of type T objects from their XML representation; stores them in this.Items.
/// </summary>
/// <param name="reader">The System.Xml.XmlReader stream from which the objects are deserialized.</param>
public void ReadXml(XmlReader reader) {
Map map = loadSchema();
int depth = reader.Depth;
List<T> items = new List<T>();
if (!reader.IsEmptyElement && reader.Read()) {
// While the reader is at a greater depth that the initial depth, ie. at one of the elements
// inside the list wrapper, the initial depth being that of the list wrapper <ItemList>...
while (reader.Depth > depth) {
try { items.Add((T)map[reader.LocalName].Deserialize(reader)); }
catch (InvalidOperationException iopEx) {
if (
iopEx.InnerException != null &&
iopEx.InnerException.Message.StartsWith("The specified type was not recognized")
) { throw new InvalidOperationException("Couldn't deserialize node '" + reader.LocalName + "' because although its element node is a valid type, its attribute-specified type was not recognized. Perhaps it needs adding to the ItemList using XmlIncludeAttribute?", iopEx); }
}
catch (KeyNotFoundException knfEx) {
throw new InvalidOperationException("Couldn't deserialize node '" + reader.LocalName + "' because its element node was not recognized as a valid type. Perhaps it needs adding to the ItemList using XmlIncludeAttribute?", knfEx);
}
catch (Exception ex) {
throw ex;
}
}
}
this.Items = items;
}
/// <summary>
/// Converts a list of type T objects into their XML representation; writes them to the specified writer.
/// </summary>
/// <param name="writer">The System.Xml.XmlWriter stream to which the objects are serialized.</param>
public void WriteXml(XmlWriter writer) {
Map map = loadSchema();
foreach (T item in this.Items) {
map[xmlTypeName(item.GetType())].Serialize(writer, item);
}
}
#endregion
#region Public properties
public List<T> Items { get; set; }
#endregion
}
/// <summary>
/// A regular person.
/// </summary>
[XmlType(AnonymousType = false, TypeName = "Person", Namespace = "")]
[XmlInclude(typeof(PersonBilingual))]
public class Person {
public string FullName { get; set; }
public int Age { get; set; }
public string Language { get; set; }
}
/// <summary>
/// A person who can speak a second language.
/// </summary>
[XmlType(AnonymousType = false, TypeName = "PersonBilingual", Namespace = "")]
public class PersonBilingual : Person {
public string SecondLanguage { get; set; }
}
/// <summary>
/// Some kind of account.
/// </summary>
[XmlType(AnonymousType = false, TypeName = "Account", Namespace = "")]
[XmlInclude(typeof(AccountBank))]
public class Account {
public string AcctName { get; set; }
public string WithCompany { get; set; }
}
/// <summary>
/// A bank account.
/// </summary>
[XmlType(AnonymousType = false, TypeName = "AccountBank", Namespace = "")]
public class AccountBank : Account {
public int BalanceInEuros { get; set; }
}
}
谢谢大家的帮助!
