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XmlElementAttribute.DataType Property

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

[Visual Basic]
Public Property DataType As String
[C#]
public string DataType {get; set;}
[C++]
public: __property String* get_DataType();
public: __property void set_DataType(String*);
[JScript]
public function get DataType() : String;
public function set DataType(String);

Property Value

An XML Schema data type, as defined by the World Wide Web Consortium (www.w3.org) document named "XML Schema Part 2: Datatypes".

Exceptions

Exception Type Condition
Exception The XML Schema data type you've specified cannot be mapped to the .NET data type.

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. Not that this will not change the serialization format, 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 then passing it as an XML Schema attribute.

For more information about XML data types, see the World Wide Web Consortium (www.w3.org) 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

Example

[Visual Basic, C#, C++] 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, specifying different DataType values for each instance. Each instance enables the XmlSerializer serialize the specified types inserted into the array.

[Visual Basic] 
Imports System
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


[C#] 
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();
   }
}


[C++] 
#using <mscorlib.dll>
#using <System.Xml.dll>
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::IO;
using namespace System::Xml::Serialization;

public __gc 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. */ 
public:
   [XmlElement(DataType = S"string",
      Type = __typeof(String),
      Namespace = S"http://www.cpandl.com"),
      XmlElement(DataType = S"int", 
      Namespace = S"http://www.cohowinery.com",
      Type = __typeof(Int32))]
   ArrayList* ExtraInfo;
};

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(S"hello");
   myGroup->ExtraInfo->Add(__box(100));

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

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

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

XmlElementAttribute Class | XmlElementAttribute Members | System.Xml.Serialization Namespace

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