XmlArrayItemAttribute::Type Property

 

Gets or sets the type allowed in an array.

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

public:
property Type^ Type {
	Type^ get();
	void set(Type^ value);
}

Property Value

Type: System::Type^

A Type that is allowed in the array.

Use the Type property to specify an overridden type for a public field or public read/write property value.

If a field or property returns an array of type Object, apply multiple instances of the XmlArrayItemAttribute to the field or property. For each instance, set the Type property to a type of object that can be inserted into the array.

If an array contains only primitive types, you do not need to apply the XmlArrayItemAttribute. By default, the XmlSerializer generates a series of elements, each with the same element name, for each value, but the type of each element is set to the XML Schema data type. For example, the following code:

' Visual Basic code
Public Class Arrays
   Public XSDTypes ()As Object= New Object(){"one", 2, 3.0}
End Class
// C# code
public class MyArray{
   // No XmlArrayItemAttribute is applied.
   public object[] XSDTypes= new object[]{"one", 2, 3.2};
}

results in this XML:

<?xml version="1.0" encoding="utf-8"?>
<Arrays xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <XSDTypes>
    <Object xsi:type="xsd:string">one</Object>
    <Object xsi:type="xsd:int">2</Object>
    <Object xsi:type="xsd:double">3</Object>
  </XSDTypes>
</Arrays>

However, if you specify the Type property for each primitive type, the element name for each value is generated using the .NET type name. For example this code:

' Visual Basic code
Public Class Arrays
   <XmlArrayItem(GetType(String)), _
   XmlArrayItem(GetType(Integer)), _
   XmlArrayItem(GetType(Double))> _
   Public PrimitiveTypes () As Object = New Object(){"one", 2, 3.0}
End Class
// C# code
public class Arrays{
   [XmlArrayItem(typeof(string))]
   [XmlArrayItem(typeof(int))]
   [XmlArrayItem(typeof(double))]
   public object [] PrimitiveTypes = new object[]{"one", 2, 3.0};
}

results in this XML:

<?xml version="1.0" encoding="utf-8"?>
<Arrays xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <PrimitiveTypes>
    <string>one</string>
    <int>2</int>
    <double>3</double>
  </PrimitiveTypes>
</Arrays>

The following example serializes an array of objects. The field that returns the array is attributed with two XmlArrayItemAttribute instances. Each instance instructs the XmlSerializer to accept the specified Type in the array.

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

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

public ref class Person
{
public:
   String^ Name;
};

public ref class Manager: public Person
{
public:
   int Rank;
};

public ref class Group
{
public:

   /* The Type property instructs the XmlSerializer to accept both
      the Person and Manager types in the array. */

   [XmlArrayItem(Type=Manager::typeid),
   XmlArrayItem(Type=Person::typeid)]
   array<Person^>^Staff;
};

void SerializeOrder( String^ filename )
{
   // Creates an XmlSerializer.
   XmlSerializer^ xSer = gcnew XmlSerializer( Group::typeid );

   // Creates the Group object, and two array items.
   Group^ myGroup = gcnew Group;
   Person^ p1 = gcnew Person;
   p1->Name = "Jacki";
   Manager^ p2 = gcnew Manager;
   p2->Name = "Megan";
   p2->Rank = 2;
   array<Person^>^myStaff = {p1,p2};
   myGroup->Staff = myStaff;

   // Serializes the object, and closes the StreamWriter.
   TextWriter^ writer = gcnew StreamWriter( filename );
   xSer->Serialize( writer, myGroup );
}

int main()
{
   SerializeOrder( "TypeEx.xml" );
}

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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