XmlSerializer.UnknownAttribute 事件

定义

XmlSerializer 在反序列化过程中遇到未知类型的 XML 特性时发生。Occurs when the XmlSerializer encounters an XML attribute of unknown type during deserialization.

public:
 event System::Xml::Serialization::XmlAttributeEventHandler ^ UnknownAttribute;
public event System.Xml.Serialization.XmlAttributeEventHandler UnknownAttribute;
member this.UnknownAttribute : System.Xml.Serialization.XmlAttributeEventHandler 
Public Custom Event UnknownAttribute As XmlAttributeEventHandler 

示例

下面的示例将打印有关反序列化 XML 文档时遇到的任何未知属性的信息。The following example prints information about any unknown attributes encountered while deserializing an XML document.

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;
using namespace System::Xml;
using namespace System::Xml::Schema;

public ref class Group
{
public:
   String^ GroupName;
};

public ref class Test
{
public:
   static void main()
   {
      Test^ t = gcnew Test;
      
      // Deserialize the file containing unknown elements.
      t->DeserializeObject( "UnknownAttributes.xml" );
   }

private:
   void Serializer_UnknownAttribute( Object^ sender, XmlAttributeEventArgs^ e )
   {
      Console::WriteLine( "Unknown Attribute" );
      Console::WriteLine( "\t{0} {1}", e->Attr->Name, e->Attr->InnerXml );
      Console::WriteLine( "\t LineNumber: {0}", e->LineNumber );
      Console::WriteLine( "\t LinePosition: {0}", e->LinePosition );
      Group^ x = dynamic_cast<Group^>(e->ObjectBeingDeserialized);
      Console::WriteLine( x->GroupName );
      Console::WriteLine( sender );
   }

   void DeserializeObject( String^ filename )
   {
      XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid );

      // Add a delegate to handle unknown element events.
      ser->UnknownAttribute += gcnew XmlAttributeEventHandler( this, &Test::Serializer_UnknownAttribute );

      // A FileStream is needed to read the XML document.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      Group^ g = dynamic_cast<Group^>(ser->Deserialize( fs ));
      fs->Close();
   }
};

int main()
{
   Test::main();
}
using System;
using System.IO;
using System.Xml.Serialization;
using System.Xml;
using System.Xml.Schema;

public class Group{
   public string GroupName;
}

public class Test{
   static void Main(){
      Test t = new Test();
      // Deserialize the file containing unknown elements.
      t.DeserializeObject("UnknownAttributes.xml");
   }
   private void Serializer_UnknownAttribute(object sender, XmlAttributeEventArgs e){
      Console.WriteLine("Unknown Attribute");
      Console.WriteLine("\t" + e.Attr.Name + " " + e.Attr.InnerXml);
      Console.WriteLine("\t LineNumber: " + e.LineNumber);
      Console.WriteLine("\t LinePosition: " + e.LinePosition);
      
      Group x  = (Group) e.ObjectBeingDeserialized;
      Console.WriteLine (x.GroupName);
      Console.WriteLine (sender.ToString());
   }
   private void DeserializeObject(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      // Add a delegate to handle unknown element events.
      ser.UnknownAttribute+=new XmlAttributeEventHandler(Serializer_UnknownAttribute);
      // A FileStream is needed to read the XML document.
     FileStream fs = new FileStream(filename, FileMode.Open);
     Group g = (Group) ser.Deserialize(fs);
     fs.Close();
    }
}
Imports System.IO
Imports System.Xml.Serialization
Imports System.Xml
Imports System.Xml.Schema

Public Class Group
   Public GroupName As String 
End Class

Public Class Test
   Shared Sub Main()
      Dim t As Test = new Test()
      ' Deserialize the file containing unknown elements.
      t.DeserializeObject("UnknownAttributes.xml")
   End Sub

   Private Sub Serializer_UnknownAttribute _
   (sender As Object , e As XmlAttributeEventArgs)
      Console.WriteLine("Unknown Attribute")
      Console.WriteLine(ControlChars.Tab & e.Attr.Name + " " & e.Attr.InnerXml)
      Console.WriteLine(ControlChars.Tab & e.LineNumber & ":"  & e.LineNumber)
      Console.WriteLine(ControlChars.Tab & e.LinePosition & ":"   & e.LinePosition)
      
      Dim x As Group = CType( e.ObjectBeingDeserialized, Group)
      Console.WriteLine (x.GroupName)
      Console.WriteLine (sender.ToString())
   End Sub
   
   Private Sub DeserializeObject(filename As String)
      Dim ser As XmlSerializer = new XmlSerializer(GetType(Group))
      ' Add a delegate to handle unknown element events.
      AddHandler ser.UnknownAttribute, _
      AddressOf Serializer_UnknownAttribute 
      ' A FileStream is needed to read the XML document.
     Dim fs As FileStream  = new FileStream(filename, FileMode.Open)
     Dim g  As Group = CType(ser.Deserialize(fs),Group)
     fs.Close()
   End Sub
End Class

注解

默认情况下,在调用 Deserialize 方法后,XmlSerializer 忽略未知类型的 XML 属性。By default, after calling the Deserialize method, the XmlSerializer ignores XML attributes of unknown types. 但是,可以使用此事件来处理此类节点类型。However, you can use this event to handle such node types.

如果正在反序列化的类的实例包含一个字段,该字段返回 XmlAttribute 对象的数组,并且已对该字段应用了一个 XmlAnyAttributeAttribute,则 UnknownAttribute 事件不会发生。If the instance of the class being deserialized contains a field that returns an array of XmlAttribute objects and an XmlAnyAttributeAttribute has been applied to the field, the UnknownAttribute event does not occur. 相反,所有未知 XML 特性都将收集到数组中。Instead, all unknown XML attributes are collected into the array.

适用于

另请参阅