XmlAttributes 類別

定義

表示用來控制 XmlSerializer 序列化與還原序列化物件方式的屬性 (Attribute) 物件集合。Represents a collection of attribute objects that control how the XmlSerializer serializes and deserializes an object.

public ref class XmlAttributes
public class XmlAttributes
type XmlAttributes = class
Public Class XmlAttributes
繼承
XmlAttributes

範例

下列範例會序列化名為之類別的實例 Orchestra ,其中包含名為的單一欄位, Instruments 該欄位會傳回物件的陣列 InstrumentThe following example serializes an instance of a class named Orchestra, which contains a single field named Instruments that returns an array of Instrument objects. 名為的第二個類別會 Brass 繼承自 Instrument 類別。A second class named Brass inherits from the Instrument class. 此範例會建立 XmlAttributes 物件以覆寫 Instrument 欄位--允許欄位接受 Brass 物件,並將 XmlAttributes 物件加入至類別的實例 XmlAttributeOverridesThe example creates an XmlAttributes object to override the Instrument field--allowing the field to accept Brass objects--and adds the XmlAttributes object to an instance of the XmlAttributeOverrides class.

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

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;
public ref class Instrument
{
public:
   String^ Name;
};

public ref class Brass: public Instrument
{
public:
   bool IsValved;
};

public ref class Orchestra
{
public:
   array<Instrument^>^Instruments;
};

void SerializeObject( String^ filename )
{
   /* Each overridden field, property, or type requires 
      an XmlAttributes object. */
   XmlAttributes^ attrs = gcnew XmlAttributes;

   /* Create an XmlElementAttribute to override the 
      field that returns Instrument objects. The overridden field
      returns Brass objects instead. */
   XmlElementAttribute^ attr = gcnew XmlElementAttribute;
   attr->ElementName = "Brass";
   attr->Type = Brass::typeid;

   // Add the element to the collection of elements.
   attrs->XmlElements->Add( attr );

   // Create the XmlAttributeOverrides object.
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

   /* Add the type of the class that contains the overridden 
      member and the XmlAttributes to override it with to the 
      XmlAttributeOverrides object. */
   attrOverrides->Add( Orchestra::typeid, "Instruments", attrs );

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );

   // Writing the file requires a TextWriter.
   TextWriter^ writer = gcnew StreamWriter( filename );

   // Create the object that will be serialized.
   Orchestra^ band = gcnew Orchestra;

   // Create an object of the derived type.
   Brass^ i = gcnew Brass;
   i->Name = "Trumpet";
   i->IsValved = true;
   array<Instrument^>^myInstruments = {i};
   band->Instruments = myInstruments;

   // Serialize the object.
   s->Serialize( writer, band );
   writer->Close();
}

void DeserializeObject( String^ filename )
{
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
   XmlAttributes^ attrs = gcnew XmlAttributes;

   // Create an XmlElementAttribute to override the Instrument.
   XmlElementAttribute^ attr = gcnew XmlElementAttribute;
   attr->ElementName = "Brass";
   attr->Type = Brass::typeid;

   // Add the element to the collection of elements.
   attrs->XmlElements->Add( attr );
   attrOverrides->Add( Orchestra::typeid, "Instruments", attrs );

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );
   FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
   Orchestra^ band = dynamic_cast<Orchestra^>(s->Deserialize( fs ));
   Console::WriteLine( "Brass:" );

   /* The difference between deserializing the overridden 
      XML document and serializing it is this: To read the derived 
      object values, you must declare an object of the derived type 
      (Brass), and cast the Instrument instance to it. */
   Brass^ b;
   System::Collections::IEnumerator^ myEnum = band->Instruments->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Instrument^ i = safe_cast<Instrument^>(myEnum->Current);
      b = dynamic_cast<Brass^>(i);
      Console::WriteLine( "{0}\n{1}", b->Name, b->IsValved );
   }
}

int main()
{
   SerializeObject( "Override.xml" );
   DeserializeObject( "Override.xml" );
}
using System;
using System.IO;
using System.Xml.Serialization;

public class Orchestra
{
   public Instrument[] Instruments;
}

public class Instrument
{
   public string Name;
}

public class Brass:Instrument
{
   public bool IsValved;
}

public class Run
{
    public static void Main()
    {
       Run test = new Run();
       test.SerializeObject("Override.xml");
       test.DeserializeObject("Override.xml");
    }

    public void SerializeObject(string filename)
    {
      /* Each overridden field, property, or type requires
      an XmlAttributes object. */
      XmlAttributes attrs = new XmlAttributes();

      /* Create an XmlElementAttribute to override the
      field that returns Instrument objects. The overridden field
      returns Brass objects instead. */
      XmlElementAttribute attr = new XmlElementAttribute();
      attr.ElementName = "Brass";
      attr.Type = typeof(Brass);

      // Add the element to the collection of elements.
      attrs.XmlElements.Add(attr);

      // Create the XmlAttributeOverrides object.
      XmlAttributeOverrides attrOverrides = new XmlAttributeOverrides();

      /* Add the type of the class that contains the overridden
      member and the XmlAttributes to override it with to the
      XmlAttributeOverrides object. */
      attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s =
      new XmlSerializer(typeof(Orchestra), attrOverrides);

      // Writing the file requires a TextWriter.
      TextWriter writer = new StreamWriter(filename);

      // Create the object that will be serialized.
      Orchestra band = new Orchestra();

      // Create an object of the derived type.
      Brass i = new Brass();
      i.Name = "Trumpet";
      i.IsValved = true;
      Instrument[] myInstruments = {i};
      band.Instruments = myInstruments;

      // Serialize the object.
      s.Serialize(writer,band);
      writer.Close();
   }

   public void DeserializeObject(string filename)
   {
      XmlAttributeOverrides attrOverrides =
         new XmlAttributeOverrides();
      XmlAttributes attrs = new XmlAttributes();

      // Create an XmlElementAttribute to override the Instrument.
      XmlElementAttribute attr = new XmlElementAttribute();
      attr.ElementName = "Brass";
      attr.Type = typeof(Brass);

      // Add the element to the collection of elements.
      attrs.XmlElements.Add(attr);

      attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s =
      new XmlSerializer(typeof(Orchestra), attrOverrides);

      FileStream fs = new FileStream(filename, FileMode.Open);
      Orchestra band = (Orchestra) s.Deserialize(fs);
      Console.WriteLine("Brass:");

      /* The difference between deserializing the overridden
      XML document and serializing it is this: To read the derived
      object values, you must declare an object of the derived type
      (Brass), and cast the Instrument instance to it. */
      Brass b;
      foreach(Instrument i in band.Instruments)
      {
         b = (Brass)i;
         Console.WriteLine(
         b.Name + "\n" +
         b.IsValved);
      }
   }
}

Imports System.IO
Imports System.Xml.Serialization

Public Class Orchestra
    Public Instruments() As Instrument
End Class

Public Class Instrument
    Public Name As String
End Class

Public Class Brass
    Inherits Instrument
    Public IsValved As Boolean
End Class


Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("Override.xml")
        test.DeserializeObject("Override.xml")
    End Sub    
    
    Public Sub SerializeObject(ByVal filename As String)
        ' Each overridden field, property, or type requires
        ' an XmlAttributes object. 
        Dim attrs As New XmlAttributes()
        
        ' Create an XmlElementAttribute to override the
        ' field that returns Instrument objects. The overridden field
        ' returns Brass objects instead. 
        Dim attr As New XmlElementAttribute()
        attr.ElementName = "Brass"
        attr.Type = GetType(Brass)
        
        ' Add the element to the collection of elements.
        attrs.XmlElements.Add(attr)
        
        ' Create the XmlAttributeOverrides object.
        Dim attrOverrides As New XmlAttributeOverrides()
        
        ' Add the type of the class that contains the overridden
        ' member and the XmlAttributes to override it with to the
        ' XmlAttributeOverrides object. 
        attrOverrides.Add(GetType(Orchestra), "Instruments", attrs)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        ' Writing the file requires a TextWriter.
        Dim writer As New StreamWriter(filename)
        
        ' Create the object that will be serialized.
        Dim band As New Orchestra()
        
        ' Create an object of the derived type.
        Dim i As New Brass()
        i.Name = "Trumpet"
        i.IsValved = True
        Dim myInstruments() As Instrument = {i}
        band.Instruments = myInstruments
        
        ' Serialize the object.
        s.Serialize(writer, band)
        writer.Close()
    End Sub
    
    
    Public Sub DeserializeObject(ByVal filename As String)
        Dim attrOverrides As New XmlAttributeOverrides()
        Dim attrs As New XmlAttributes()
        
        ' Create an XmlElementAttribute to override the Instrument.
        Dim attr As New XmlElementAttribute()
        attr.ElementName = "Brass"
        attr.Type = GetType(Brass)
        
        ' Add the element to the collection of elements.
        attrs.XmlElements.Add(attr)
        
        attrOverrides.Add(GetType(Orchestra), "Instruments", attrs)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        Dim fs As New FileStream(filename, FileMode.Open)
        Dim band As Orchestra = CType(s.Deserialize(fs), Orchestra)
        Console.WriteLine("Brass:")
        
        ' The difference between deserializing the overridden
        ' XML document and serializing it is this: To read the derived
        ' object values, you must declare an object of the derived type
        ' (Brass), and cast the Instrument instance to it. 
        Dim b As Brass
        Dim i As Instrument
        For Each i In  band.Instruments
            b = CType(i, Brass)
            Console.WriteLine(b.Name + ControlChars.Cr + _
                              b.IsValved.ToString())
        Next i
    End Sub
End Class

備註

建立 XmlAttributes 會覆寫序列化類別實例的預設方式之進程的一部分 XmlSerializerCreating the XmlAttributes is part of a process that overrides the default way the XmlSerializer serializes class instances. 例如,假設您想要序列化從具有無法存取之來源的 DLL 建立的物件。For example, suppose you want to serialize an object that is created from a DLL which has an inaccessible source. 藉由使用 XmlAttributeOverrides ,您可以加強或控制物件的序列化方式。By using the XmlAttributeOverrides, you can augment or otherwise control how the object is serialized.

類別的成員 XmlAttributes 會直接對應至控制序列化的屬性類別系列。The members of the XmlAttributes class correspond directly to a family of attribute classes that control serialization. 例如, XmlText 屬性必須設定為 XmlTextAttribute ,它可讓您藉由指示將 XmlSerializer 屬性值序列化為 XML 文字,來覆寫欄位或屬性的序列化。For example, the XmlText property must be set to an XmlTextAttribute, which allows you to override serialization of a field or property by instructing the XmlSerializer to serialize the property value as XML text. 如需控制序列化的屬性完整清單,請參閱 XmlSerializerFor a complete list of attributes that control serialization, see the XmlSerializer.

如需有關搭配類別使用的詳細資訊 XmlAttributeOverrides XmlAttributes ,請參閱 如何:指定 XML 資料流程的替代元素名稱For more details on using the XmlAttributeOverrides with the XmlAttributes class, see How to: Specify an Alternate Element Name for an XML Stream.

建構函式

XmlAttributes()

初始化 XmlAttributes 類別的新執行個體。Initializes a new instance of the XmlAttributes class.

XmlAttributes(ICustomAttributeProvider)

初始化 XmlAttributes 類別的新執行個體,並自訂 XmlSerializer 如何序列化和還原序列化物件。Initializes a new instance of the XmlAttributes class and customizes how the XmlSerializer serializes and deserializes an object.

屬性

XmlAnyAttribute

取得或設定要覆寫的 XmlAnyAttributeAttributeGets or sets the XmlAnyAttributeAttribute to override.

XmlAnyElements

取得要覆寫的 XmlAnyElementAttribute 物件的集合。Gets the collection of XmlAnyElementAttribute objects to override.

XmlArray

取得或設定物件,指定 XmlSerializer 如何序列化公用欄位或會傳回陣列的讀取/寫入屬性。Gets or sets an object that specifies how the XmlSerializer serializes a public field or read/write property that returns an array.

XmlArrayItems

取得或設定物件集合,指定 XmlSerializer 如何序列化項目 (用來插入至公用欄位或讀取/寫入屬性所傳回的陣列)。Gets or sets a collection of objects that specify how the XmlSerializer serializes items inserted into an array returned by a public field or read/write property.

XmlAttribute

取得或設定物件,指定 XmlSerializer 如何將公用欄位或公用讀取/寫入屬性序列化為 XML 屬性。Gets or sets an object that specifies how the XmlSerializer serializes a public field or public read/write property as an XML attribute.

XmlChoiceIdentifier

取得或設定物件,讓您在一組選項間進行區別。Gets or sets an object that allows you to distinguish between a set of choices.

XmlDefaultValue

取得或設定 XML 項目或屬性的預設值。Gets or sets the default value of an XML element or attribute.

XmlElements

取得物件的集合,指定 XmlSerializer 如何將公用欄位或讀取/寫入屬性序列化為 XML 項目。Gets a collection of objects that specify how the XmlSerializer serializes a public field or read/write property as an XML element.

XmlEnum

取得或設定物件,指定 XmlSerializer 如何序列化列舉型別 (Enumeration) 成員。Gets or sets an object that specifies how the XmlSerializer serializes an enumeration member.

XmlIgnore

取得或設定數值,指定 XmlSerializer 是否要序列化公用欄位或公用讀取/寫入屬性。Gets or sets a value that specifies whether or not the XmlSerializer serializes a public field or public read/write property.

Xmlns

取得或設定數值,指定當物件包含傳回已覆寫 XmlSerializerNamespaces 物件的成員時,是否要保留所有的命名空間宣告。Gets or sets a value that specifies whether to keep all namespace declarations when an object containing a member that returns an XmlSerializerNamespaces object is overridden.

XmlRoot

取得或設定物件,指定 XmlSerializer 如何將類別序列化為 XML (Root Element)。Gets or sets an object that specifies how the XmlSerializer serializes a class as an XML root element.

XmlText

取得或設定物件,指定 XmlSerializer 將公用欄位或公用讀取/寫入屬性序列化為 XML 文字。Gets or sets an object that instructs the XmlSerializer to serialize a public field or public read/write property as XML text.

XmlType

取得或設定物件,指定 XmlSerializer 如何序列化套用 XmlTypeAttribute 的類別。Gets or sets an object that specifies how the XmlSerializer serializes a class to which the XmlTypeAttribute has been applied.

方法

Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

(繼承來源 Object)
GetHashCode()

作為預設雜湊函數。Serves as the default hash function.

(繼承來源 Object)
GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(繼承來源 Object)
MemberwiseClone()

建立目前 Object 的淺層複製。Creates a shallow copy of the current Object.

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(繼承來源 Object)

適用於

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