XmlElementAttribute.DataType Property

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.ReaderWriter.dll

Source:

XmlElementAttribute.cs

Gets or sets the XML Schema definition (XSD) data type of the XML element generated by the XmlSerializer.

public:
 property System::String ^ DataType { System::String ^ get(); void set(System::String ^ value); };

public string DataType { get; set; }

member this.DataType : string with get, set

Public Property DataType As String

Property Value

String

An XML Schema data type.

Exceptions

Exception

The XML Schema data type you have specified cannot be mapped to the.NET data type.

Examples

The following example serializes a class named Group that contains a field named ExtraInfo, which returns an ArrayList. The example applies two instances of the XmlElementAttribute to the field and specifies different DataType values for each instance. Each instance enables the XmlSerializer to serialize the specified types inserted into the array.

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

using namespace System;
using namespace System::Collections;
using namespace System::IO;
using namespace System::Xml::Serialization;
public ref class Group
{
public:

   /* Apply two XmlElementAttributes to the field. Set the DataType
      to string an int to allow the ArrayList to accept 
      both types. The Namespace is also set to different values
      for each type. */

   [XmlElement(DataType="string",
   Type=String::typeid,
   Namespace="http://www.cpandl.com"),
   XmlElement(DataType="snippet1>",
   Namespace="http://www.cohowinery.com",
   Type=Int32::typeid)]
   ArrayList^ ExtraInfo;
};

void SerializeObject( String^ filename )
{
   // A TextWriter is needed to write the file.
   TextWriter^ writer = gcnew StreamWriter( filename );

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

   // Create the object to serialize.
   Group^ myGroup = gcnew Group;

   /* Add a string and an integer to the ArrayList returned
      by the ExtraInfo field. */
   myGroup->ExtraInfo = gcnew ArrayList;
   myGroup->ExtraInfo->Add( "hello" );
   myGroup->ExtraInfo->Add( 100 );

   // Serialize the object and close the TextWriter.
   s->Serialize( writer, myGroup );
   writer->Close();
}

int main()
{
   SerializeObject( "ElementTypes.xml" );
}

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

public class Group
{
   /* Apply two XmlElementAttributes to the field. Set the DataType
      to string an int to allow the ArrayList to accept
      both types. The Namespace is also set to different values
      for each type. */
   [XmlElement(DataType = "string",
   Type = typeof(string),
   Namespace = "http://www.cpandl.com"),
   XmlElement(DataType = "int",
   Namespace = "http://www.cohowinery.com",
   Type = typeof(int))]
   public ArrayList ExtraInfo;
}

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

    public void SerializeObject(string filename)
    {
      // A TextWriter is needed to write the file.
      TextWriter writer = new StreamWriter(filename);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s =
      new XmlSerializer(typeof(Group));

      // Create the object to serialize.
      Group myGroup = new Group();

      /* Add a string and an integer to the ArrayList returned
         by the ExtraInfo field. */
      myGroup.ExtraInfo = new ArrayList();
      myGroup.ExtraInfo.Add("hello");
      myGroup.ExtraInfo.Add(100);

      // Serialize the object and close the TextWriter.
      s.Serialize(writer,myGroup);
      writer.Close();
   }
}

Imports System.Collections
Imports System.IO
Imports System.Xml.Serialization


Public Class Group
    ' Apply two XmlElementAttributes to the field. Set the DataType
    ' to string and int to allow the ArrayList to accept
    ' both types. The Namespace is also set to different values
    ' for each type. 
    <XmlElement(DataType := "string", _
        Type := GetType(String), _
        Namespace := "http://www.cpandl.com"), _
     XmlElement(DataType := "int", _                    
        Type := GetType(Integer), _
        Namespace := "http://www.cohowinery.com")> _
    Public ExtraInfo As ArrayList
End Class


Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("ElementTypes.xml")
    End Sub    
    
    Public Sub SerializeObject(filename As String)
        ' A TextWriter is needed to write the file.
        Dim writer As New StreamWriter(filename)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Group))
        
        ' Create the object to serialize.
        Dim myGroup As New Group()
        
        ' Add a string and an integer to the ArrayList returned
        ' by the ExtraInfo field. 
        myGroup.ExtraInfo = New ArrayList()
        myGroup.ExtraInfo.Add("hello")
        myGroup.ExtraInfo.Add(100)
        
        ' Serialize the object and close the TextWriter.
        s.Serialize(writer, myGroup)
        writer.Close()
    End Sub
End Class

Remarks

The following table lists the XML Schema simple data types with their.NET equivalents.

For the XML Schema base64Binary and hexBinary data types, use an array of Byte structures, and apply a XmlElementAttribute with the DataType set to "base64Binary" or "hexBinary", as appropriate. For the XML Schema time and date data types, use the DateTime type and apply the XmlElementAttribute with the DataType set to "date" or "time".

For every XML Schema type that is mapped to a string, apply the XmlElementAttribute with its DataType property set to the XML Schema type. It is possible that this can change the serialization format, not only the schema for the member.

Note

The property is case-sensitive, so you must set it exactly to one of the XML Schema data types.

Note

Passing binary data as an XML element is more efficient than passing it as an XML Schema attribute.

For more information about XML data types, see the World Wide Web Consortium document named XML Schema Part 2: Datatypes.

XSD data type	.NET data type
anyURI	String
base64Binary	Array of Byte objects
boolean	Boolean
byte	SByte
date	DateTime
dateTime	DateTime
decimal	Decimal
double	Double
ENTITY	String
ENTITIES	String
float	Single
gDay	String
gMonth	String
gMonthDay	String
gYear	String
gYearMonth	String
hexBinary	Array of Byte objects
ID	String
IDREF	String
IDREFS	String
int	Int32
integer	String
language	String
long	Int64
Name	String
NCName	String
negativeInteger	String
NMTOKEN	String
NMTOKENS	String
normalizedString	String
nonNegativeInteger	String
nonPositiveInteger	String
NOTATION	String
positiveInteger	String
QName	XmlQualifiedName
duration	String
string	String
short	Int16
time	DateTime
token	String
unsignedByte	Byte
unsignedInt	UInt32
unsignedLong	UInt64
unsignedShort	UInt16