XmlAttributeEventHandler 代理人

定義

public delegate void XmlAttributeEventHandler(System::Object ^ sender, XmlAttributeEventArgs ^ e);

public delegate void XmlAttributeEventHandler(object sender, XmlAttributeEventArgs e);

type XmlAttributeEventHandler = delegate of obj * XmlAttributeEventArgs -> unit

Public Delegate Sub XmlAttributeEventHandler(sender As Object, e As XmlAttributeEventArgs)

參數

範例

以下範例將一個名為 UnknownAttributes.xml的檔案中所命名 Group 的類別反序列化。 每當檔案中發現某元素在類別中沒有對應成員時，事件 UnknownAttribute 就會發生。 要嘗試範例，請將以下 XML 程式碼貼上到名為 UnknownAttributes.xml的檔案中。

<?xml version="1.0" encoding="utf-8"?>
<Group xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" GroupType = 'Technical' GroupNumber = '42' GroupBase = 'Red'>
  <GroupName>MyGroup</GroupName>
</Group>

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

備註

當你建立 XmlAttributeEventHandler 代理人時，你會確定處理事件的方法。 要將事件與你的事件處理器關聯，請將該代理的實例加入事件中。 事件處理程序會在事件發生時被呼叫，除非你移除代理。 欲了解更多關於事件處理代理的資訊，請參閱 「處理與提升事件」。

UnknownAttribute該事件僅在物件Deserialize被反序列化時發生。

另請參閱

• XmlNodeEventHandler
• Deserialize(Stream)
• XmlSerializer
• XmlAttributes
• XML 序列化簡介
• 如何：為 XML 串流指定替代元素名稱
• 使用屬性控制 XML 串行化
• XML 序列化範例
• XML 架構定義工具 （Xsd.exe）