如何使用 XmlSerializer 序列化 System.Type 对象？

Question

考虑这种类型：

  [DataContract]
  public class EntityId
  {
    [DataMember(Order = 1)]
    public string IdAsString { get; set; }
    [DataMember(Order = 2)]
    public Type Type { get; set; }
  }

我为它创建了一个 Xml 序列化程序程序集。但是，尝试对其进行序列化会产生异常：

System.InvalidOperationException occurred
  Message=The type NC.DTO.FlowFolder was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.
  Source=NC.DTO.XmlSerializers
  StackTrace:
       at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write3_Type(String n, String ns, Type o, Boolean isNullable, Boolean needType)
  InnerException: 

NC.DTO.FlowFolder 实际上是 typeof(NC.DTO.FlowFolder) 的字符串表示形式 - Xml 序列化程序知道 NC.DTO.FlowFolder 类型，但似乎无法序列化的是 Type对象本身。

反射器显示失败的方法内容：

private void Write3_Type(string n, string ns, Type o, bool isNullable, bool needType)
{
    if (o == null)
    {
        if (isNullable)
        {
            base.WriteNullTagLiteral(n, ns);
        }
    }
    else if (!needType && (o.GetType() != typeof(Type)))
    {
        throw base.CreateUnknownTypeException(o);
    }
}

注意throw 声明。

堆栈跟踪是：

NC.DTO.XmlSerializers.dll!Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write3_Type(string n, string ns, System.Type o, bool isNullable, bool needType) + 0xda bytes    
NC.DTO.XmlSerializers.dll!Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write11_EntityId(string n, string ns, NC.DTO.EntityId o, bool isNullable, bool needType) + 0x2a8 bytes  
NC.DTO.XmlSerializers.dll!Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write14_FlowFolder(string n, string ns, NC.DTO.FlowFolder o, bool isNullable, bool needType) + 0x36b bytes  
NC.DTO.XmlSerializers.dll!Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write42_FlowFolder(object o) + 0xc9 bytes   
[Native to Managed Transition]  
System.Xml.dll!System.Xml.Serialization.TempAssembly.InvokeWriter(System.Xml.Serialization.XmlMapping mapping, System.Xml.XmlWriter xmlWriter, object o, System.Xml.Serialization.XmlSerializerNamespaces namespaces, string encodingStyle, string id) Line 342 + 0xb9 bytes    C#
System.Xml.dll!System.Xml.Serialization.XmlSerializer.Serialize(System.Xml.XmlWriter xmlWriter, object o, System.Xml.Serialization.XmlSerializerNamespaces namespaces, string encodingStyle, string id) Line 676 + 0xdf bytes   C#
System.Xml.dll!System.Xml.Serialization.XmlSerializer.Serialize(System.Xml.XmlWriter xmlWriter, object o, System.Xml.Serialization.XmlSerializerNamespaces namespaces, string encodingStyle) Line 646   C#
System.Xml.dll!System.Xml.Serialization.XmlSerializer.Serialize(System.Xml.XmlWriter xmlWriter, object o, System.Xml.Serialization.XmlSerializerNamespaces namespaces) Line 640 C#
System.Xml.dll!System.Xml.Serialization.XmlSerializer.Serialize(System.Xml.XmlWriter xmlWriter, object o) Line 616  C#

我的问题是如何让 Xml 序列化程序乐于序列化和反序列化 EntityId 对象？

谢谢。

附言

如果有人知道另一种 Xml 序列化库，可以将 XML 序列化为 Newtonsoft.Json 到 JSON 序列化 - 请分享。

Answer 1

xml 通常旨在独立于平台，因此为什么它不起作用。你可以试试：

[XmlIgnore]
public Type Type { get; set; }
[XmlElement("Type")]
[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
public string AssemblyQualifiedTypeName
{
    get { return Type == null ? null : Type.AssemblyQualifiedName; }
    set { Type = string.IsNullOrEmpty(value) ? null : Type.GetType(value); }
}

另请注意，如果您使用XmlSerializer，则数据合同属性无效。另请注意，这会将您绑定到 .NET 和可能的特定版本等。