XmlTextAttribute Třída

Definice

public ref class XmlTextAttribute : Attribute

[System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue)]
public class XmlTextAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue)>]
type XmlTextAttribute = class
    inherit Attribute

Public Class XmlTextAttribute
Inherits Attribute

Dědičnost

Object

Attribute

XmlTextAttribute

Atributy

AttributeUsageAttribute

Příklady

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

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

public ref class Group1
{
public:

   // The XmlTextAttribute with type set to string informs the 
   // XmlSerializer that strings should be serialized as XML text.

   [XmlText(String::typeid)]
   [XmlElement(Int32::typeid)]
   [XmlElement(Double::typeid)]
   array<Object^>^All;
   Group1()
   {
      array<Object^>^temp = {321,"One",2,3.0,"Two"};
      All = temp;
   }
};

public enum class GroupType
{
   Small, Medium, Large
};

public ref class Group2
{
public:

   [XmlText(Type=GroupType::typeid)]
   GroupType Type;
};

public ref class Group3
{
public:

   [XmlText(Type=DateTime::typeid)]
   DateTime CreationTime;
   Group3()
   {
      CreationTime = DateTime::Now;
   }
};

public ref class Test
{
public:
   static void main()
   {
      Test^ t = gcnew Test;
      t->SerializeArray( "XmlText1.xml" );
      t->SerializeEnum( "XmlText2.xml" );
      t->SerializeDateTime( "XmlText3.xml" );
   }

private:
   void SerializeArray( String^ filename )
   {
      XmlSerializer^ ser = gcnew XmlSerializer( Group1::typeid );
      Group1^ myGroup1 = gcnew Group1;
      TextWriter^ writer = gcnew StreamWriter( filename );
      ser->Serialize( writer, myGroup1 );
      writer->Close();
   }

   void SerializeEnum( String^ filename )
   {
      XmlSerializer^ ser = gcnew XmlSerializer( Group2::typeid );
      Group2^ myGroup = gcnew Group2;
      myGroup->Type = GroupType::Medium;
      TextWriter^ writer = gcnew StreamWriter( filename );
      ser->Serialize( writer, myGroup );
      writer->Close();
   }

   void SerializeDateTime( String^ filename )
   {
      XmlSerializer^ ser = gcnew XmlSerializer( Group3::typeid );
      Group3^ myGroup = gcnew Group3;
      TextWriter^ writer = gcnew StreamWriter( filename );
      ser->Serialize( writer, myGroup );
      writer->Close();
   }
};

int main()
{
   Test::main();
}

using System;
using System.Xml.Serialization;
using System.IO;

public class Group1{
   // The XmlTextAttribute with type set to string informs the
   // XmlSerializer that strings should be serialized as XML text.
   [XmlText(typeof(string))]
   [XmlElement(typeof(int))]
   [XmlElement(typeof(double))]
   public object [] All= new object []{321, "One", 2, 3.0, "Two" };
}

public class Group2{
   [XmlText(Type = typeof(GroupType))]
   public GroupType Type;
}
public enum GroupType{
   Small,
   Medium,
   Large
}

public class Group3{
   [XmlText(Type=typeof(DateTime))]
   public DateTime CreationTime = DateTime.Now;
}

public class Test{
   static void Main(){
      Test t = new Test();
      t.SerializeArray("XmlText1.xml");
      t.SerializeEnum("XmlText2.xml");
      t.SerializeDateTime("XmlText3.xml");
   }

   private void SerializeArray(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group1));
      Group1 myGroup1 = new Group1();

      TextWriter writer = new StreamWriter(filename);

      ser.Serialize(writer, myGroup1);
      writer.Close();
   }

   private void SerializeEnum(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group2));
      Group2 myGroup = new Group2();
      myGroup.Type = GroupType.Medium;
      TextWriter writer = new StreamWriter(filename);

      ser.Serialize(writer, myGroup);
      writer.Close();
   }

   private void SerializeDateTime(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group3));
      Group3 myGroup = new Group3();
      TextWriter writer = new StreamWriter(filename);

      ser.Serialize(writer, myGroup);
      writer.Close();
   }
}

Imports System.Xml.Serialization
Imports System.IO


Public Class Group1
   ' The XmlTextAttribute with type set to String informs the 
   ' XmlSerializer that strings should be serialized as XML text.
   <XmlText(GetType(String)), _
   XmlElement(GetType(integer)), _  
   XmlElement(GetType(double))> _
   public All () As Object = _
   New Object (){321, "One", 2, 3.0, "Two" }
End Class


Public Class Group2
   <XmlText(GetType(GroupType))> _
   public Type As GroupType 
End Class

Public Enum GroupType
   Small
   Medium
   Large
End Enum

Public Class Group3
   <XmlText(GetType(DateTime))> _
   Public CreationTime As DateTime = DateTime.Now
End Class

Public Class Test
   Shared Sub Main()
      Dim t As Test = New Test()
      t.SerializeArray("XmlText1.xml")
      t.SerializeEnum("XmlText2.xml")
      t.SerializeDateTime("XmlText3.xml")
   End Sub

   Private Sub SerializeArray(filename As String)
      Dim ser As XmlSerializer = New XmlSerializer(GetType(Group1))
      Dim myGroup1 As Group1 = New Group1()

      Dim writer As TextWriter = New StreamWriter(filename)

      ser.Serialize(writer, myGroup1)
      writer.Close()
   End Sub

   Private Sub SerializeEnum(filename As String)
      Dim ser As XmlSerializer = New XmlSerializer(GetType(Group2))
      Dim myGroup As Group2 = New Group2()
      myGroup.Type = GroupType.Medium
      Dim writer As TextWriter = New StreamWriter(filename)

      ser.Serialize(writer, myGroup)
      writer.Close()
   End Sub

   Private Sub SerializeDateTime(filename As String)
      Dim ser As XmlSerializer = new XmlSerializer(GetType(Group3))
      Dim myGroup As Group3 = new Group3()
      Dim writer As TextWriter = new StreamWriter(filename)

      ser.Serialize(writer, myGroup)
      writer.Close()
   End Sub
End Class

Poznámky

Patří XmlTextAttribute do rodiny atributů, které řídí, jak XmlSerializer serializuje a deserializuje objekt (prostřednictvím svých Serialize metod a Deserialize ). Úplný seznam podobných atributů naleznete v tématu Attributes That Control XML Serialization.

Ve třídě lze použít pouze jednu instanci XmlTextAttribute třídy.

Můžete použít XmlTextAttribute na veřejná pole a veřejné vlastnosti pro čtení a zápis, které vracejí primitivní typy a typy výčtu.

Můžete použít XmlTextAttribute na pole nebo vlastnost, která vrací pole řetězců. Atribut můžete použít také na pole typu Object , ale musíte vlastnost nastavit Type na řetězec. V takovém případě jsou všechny řetězce vložené do pole serializovány jako text XML.

Lze XmlTextAttribute také použít pro pole, které vrací XmlNode nebo pole XmlNode objektů.

Ve výchozím nastavení XmlSerializer serializuje člen třídy jako element XML. Pokud však použijete XmlTextAttribute na člena, XmlSerializer přeloží jeho hodnotu na text XML. To znamená, že hodnota je zakódována do obsahu xml elementu.

Nástroj pro definici schématu XML (Xsd.exe) občas generuje XmlTextAttribute při vytváření tříd ze souboru definice schématu XML (XSD). K tomu dochází, když schéma obsahuje se smíšeným complexType obsahem; v takovém případě odpovídající třída obsahuje člen, který vrací pole řetězců, na které XmlTextAttribute je použit . Například když Xml Schema Definition nástroj zpracovává toto schéma:

<xs:schema attributeFormDefault="qualified" elementFormDefault="qualified" targetNamespace=""   
xmlns:xs="http://www.w3.org/2001/XMLSchema">  
  <xs:element name="LinkList" type="LinkList" />  
  <xs:complexType name="LinkList" mixed="true">  
    <xs:sequence>  
      <xs:element minOccurs="1" maxOccurs="1" name="id" type="xs:int" />  
      <xs:element minOccurs="0" maxOccurs="1" name="name" type="xs:string" />  
      <xs:element minOccurs="0" maxOccurs="1" name="next" type="LinkList" />  
    </xs:sequence>  
  </xs:complexType>  
</xs:schema>  

vygeneruje se následující třída (nadbytečné mezery a poznámky byly odstraněny):

[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]
public partial class LinkList
{

    private int idField;
    private string nameField;
    private LinkList nextField;
    private string[] textField;

    public int id
    {
        get
        {
            return this.idField;
        }
        set
        {
            this.idField = value;
        }
    }

    public string name
    {
        get
        {
            return this.nameField;
        }
        set
        {
            this.nameField = value;
        }
    }

    public LinkList next
    {
        get
        {
            return this.nextField;
        }
        set
        {
            this.nextField = value;
        }
    }

    [System.Xml.Serialization.XmlTextAttribute()]
    public string[] Text
    {
        get
        {
            return this.textField;
        }
        set
        {
            this.textField = value;
        }
    }
}

<System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "2.0.50727.42"), _
 System.SerializableAttribute(), _
 System.Diagnostics.DebuggerStepThroughAttribute(), _
 System.ComponentModel.DesignerCategoryAttribute("code"), _
 System.Xml.Serialization.XmlRootAttribute([Namespace]:="", IsNullable:=False)> _
Partial Public Class LinkList
    Private idField As Integer
    Private nameField As String
    Private nextField As LinkList
    Private textField() As String
    Public Property id() As Integer
        Get
            Return Me.idField
        End Get
        Set(ByVal value As Integer)
            Me.idField = value
        End Set
    End Property
    Public Property name() As String
        Get
            Return Me.nameField
        End Get
        Set(ByVal value As String)
            Me.nameField = value
        End Set
    End Property
    Public Property [next]() As LinkList
        Get
            Return Me.nextField
        End Get
        Set(ByVal value As LinkList)
            Me.nextField = value
        End Set
    End Property
    <System.Xml.Serialization.XmlTextAttribute()> _
    Public Property Text() As String()
        Get
            Return Me.textField
        End Get
        Set(ByVal value As String())
            Me.textField = value
        End Set
    End Property
End Class

Další informace o používání atributů najdete v tématu Atributy.

Viz také

• XmlAttributeOverrides
• XmlAttributes
• XmlSerializer
• XmlText
• Představení serializace XML
• Postupy: Zadání alternativního názvu elementu pro XML stream
• Řízení serializace XML pomocí atributů
• Příklady serializace XML
• Nástroj pro definici schématu XML (Xsd.exe)