The following code sample shows the newly created person class. There are several particularities in this class declaration that must not be ignored.

using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.Xml.Serialization;

namespace OnPhoneData {
  [XmlRoot("Person")]
  [Serializable]
  public class Person {
    #region IXmlSerializable Members
    public string Name { get; set; }
    #endregion
  }
}

The first one is using System.Xml.Serialization; without which serialization isn't possible at all. Indeed, this contains everything we may need for serialization purposes. The second particularity is the presence of [XmlRoot("Person")] and [Serializable] annotations. As serialization takes place in the XML file, you have to define the root name of this XML file. Therefore, the first annotation defines it. The second one enables the serialization for this particular class. While the first annotation is optional, without the second one, all attempts in serializing the person class will fail. Finally, last but not least, the #region IXmlSerializable Members and #endregion encapsulate the class' attributes you want to persist.

In the following code sample, which takes place in the MainActivity class' OnCreate() method, we use the MemoryStream() method as StreamWriter. This allows us to get rid of file-writing permissions in case we just want to send the persisted file to another client/server. Then, we create an XmlSerializer instance, which takes into an argument the type of the class we wish to serialize. In our case, the method typeof(Person) is used as an argument. We now have an XmlSerializer instance capable of serializing person objects. We will not describe the two statements following the creation of the serializer as they are pure and very simple object manipulations in C#. The last statement, however, deserves some explanation. The XmlSerializer class offers the Serialize() method, which requires a StreamWriter and an object to serialize. We give them both with the ms and Person variable.

using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.Xml.Serialization;
using System.IO;

[Activity (Label = "OnPhoneData", MainLauncher = true)]
public class MainActivity : Activity {
  protected override void OnCreate (Bundle bundle) {
    base.OnCreate (bundle);
    SetContentView (Resource.Layout.Main);
    using (var ms = new MemoryStream()) {
      XmlSerializer mySerializer = new XmlSerializer (typeof(Person));
      var Person = new Person ();
      Person.Name = "Mathieu";
      mySerializer.Serialize (ms, Person);
    }
  }
}

At this point, you can compile and deploy your application to the emulator. However, nothing will tell you if the serialization went well. Obviously, Xamarin Studio will, for sure, tell you if something went wrong. Therefore, we will seize the opportunity to instantly deserialize our object and print the result on some component of the graphical interface.

In order to deserialize our newly serialized object, we have to add the following code after our serialization, but when it is still in use. The following code sample shows the complete code and highlights the parts related to the deserialization:

protected override void OnCreate (Bundle bundle) {
  base.OnCreate (bundle);
  SetContentView (Resource.Layout.Main);
  using (var ms = new MemoryStream()) {
    XmlSerializer mySerializer = new XmlSerializer (typeof(SomeData));
    var someData = new Person ();
    someData.Name = "Mathieu";
    mySerializer.Serialize (ms, someData);
    ms.Position = 0;
    Person deserialize = (Person)mySerializer.Deserialize (ms);
    Button button = FindViewById<Button> (Resource.Id.myButton);
    button.Text = deserialize.Name;
  }
}