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XmlRootAttribute Class

Controls XML serialization of the attribute target as an XML root element.

For a list of all members of this type, see XmlRootAttribute Members.


[Visual Basic]
<AttributeUsage(AttributeTargets.Class Or AttributeTargets.Struct _
   Or AttributeTargets.Enum Or AttributeTargets.Interface Or _
Public Class XmlRootAttribute
   Inherits Attribute
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct |
   AttributeTargets.Enum | AttributeTargets.Interface |
public class XmlRootAttribute : Attribute
[AttributeUsage(AttributeTargets::Class | AttributeTargets::Struct
   | AttributeTargets::Enum | AttributeTargets::Interface |
public __gc class XmlRootAttribute : public Attribute
   AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct |
   AttributeTargets.Enum | AttributeTargets.Interface |
class XmlRootAttribute extends Attribute

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.


The XmlRootAttribute belongs to a family of attributes that controls how the XmlSerializer serializes, or deserializes, an object. For a complete list of similar attributes, see Attributes That Control XML Serialization.

You can apply the XmlRootAttribute to a class, struct, enumeration, or interface. You can also apply the attribute to the return value of an XML Web service method.

Every XML document must have a single root element that contains all the other elements. The XmlRootAttribute allows you to control how the XmlSerializer generates the root element by setting certain properties. For example, specify the name of the generated XML element by setting the ElementName property.

For more information about using attributes, see Extending Metadata Using Attributes.

Note   In your code, you can use the word XmlRoot instead of the longer XmlRootAttribute.


[Visual Basic, C#, C++] The following example applies the XmlRootAttribute to a class. The attribute specifies the element name, namespace, and whether the element is qualified, and whether the xsi:nil attribute will be generated if the class is set to a null reference (Nothing in Visual Basic).

[Visual Basic] 
Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.Schema
Imports System.Xml.Serialization

<XmlRoot(Namespace:="", _
    ElementName:="MyGroupName", _
    DataType:="string", _
    IsNullable:=True)> _
Public Class Group

    Private groupNameValue As String
    ' Insert code for the Group class.
    Public Sub New()

    End Sub

    Public Sub New(ByVal groupNameVal As String)

        groupNameValue = groupNameVal
    End Sub

    Property GroupName() As String
            Return groupNameValue
        End Get

        Set(ByVal Value As String)
            groupNameValue = Value
        End Set
    End Property
End Class

Public Class Test

    Shared Sub Main()

        Dim t As Test = New Test()
    End Sub

    Private Sub SerializeGroup()

        ' Create an instance of the Group class, and an
        ' instance of the XmlSerializer to serialize it.
        Dim myGroup As Group = New Group("Redmond")
        Dim ser As XmlSerializer = New XmlSerializer(GetType(Group))

        ' A FileStream is used to write the file.
        Dim fs As FileStream = New FileStream("group.xml", FileMode.Create)
        ser.Serialize(fs, myGroup)
        Console.WriteLine("Done... Press any key to exit.")
    End Sub

End Class

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

[XmlRoot(Namespace = "", 
     ElementName = "MyGroupName", 
     DataType = "string", 
public class Group
    private string groupNameValue;
    // Insert code for the Group class.
    public Group()
    public Group(string groupNameVal)
        groupNameValue = groupNameVal;
    public string GroupName
        get{return groupNameValue;}
        set{groupNameValue = value;}
public class Test
    static void Main()
        Test t = new Test();
    private void SerializeGroup()
        // Create an instance of the Group class, and an
        // instance of the XmlSerializer to serialize it.
        Group myGroup = new Group("Redmond");
        XmlSerializer ser = new XmlSerializer(typeof(Group));
        // A FileStream is used to write the file.
        FileStream fs = new FileStream("group.xml",FileMode.Create);

#using <mscorlib.dll>
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Schema;
using namespace System::Xml::Serialization;

[XmlRoot(Namespace = S"", 
     ElementName = S"MyGroupName", 
     DataType = S"string", 
public __gc class Group
    String* groupNameValue;
    // Insert code for the Group class.
    Group(String* groupNameVal)
        groupNameValue = groupNameVal;
    __property String* get_GroupName()
       return groupNameValue;
    __property void set_GroupName( String* value )
       groupNameValue = value;

void SerializeGroup()
   // Create an instance of the Group class, and an
   // instance of the XmlSerializer to serialize it.
   Group* myGroup = new Group(S"Redmond");
   XmlSerializer* ser = new XmlSerializer(__typeof(Group));
   // A FileStream is used to write the file.
   FileStream* fs = new FileStream(S"group.xml",FileMode::Create);

int main()

[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.


Namespace: System.Xml.Serialization

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

Assembly: System.Xml (in System.Xml.dll)

See Also

XmlRootAttribute Members | System.Xml.Serialization Namespace | XmlArrayAttribute | XmlElementAttribute | XmlSerializer | Introducing XML Serialization | Overriding XML Serialization | XmlAttributes | Controlling XML Serialization Using Attributes | Examples of XML Serialization

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