Jonathan Yong

You can ignore certain public field from being serialize if the value for that field
is not specified.

XmlSerializer recognize a specific pattern during serialization to ignore
or include a field into the serialization.

Here are the steps :
1) You create a public field (EG : public int Age).
2) Create a boolean field using the convention PropertyNameSpecified (EG : public boolean AgeSpecified).
3) Apply XmlIgnoreAttribute attribute to the boolean property.

Refer to the following code.

public class Customer
{
    public string Name;
    public int Age;

    [XmlIgnore()]
    public bool AgeSpecified;
}

Here is the code to serialize the Customer object. Notice I set the AgeSpecified to false to tell the XmlSerializer not to serialize the Age field.

static void SerializeData()
{
    Customer c = new Customer();
    c.Name = "Bob";
    c.Age = 21;
    c.AgeSpecified = false;

    XmlSerializer serializer = new XmlSerializer(typeof(Customer));
    FileStream fs = new FileStream("simple.xml", FileMode.Create);

    // Serialize the object
    serializer.Serialize(fs, c);
    fs.Close();
}

If you open simple.xml in notepad, you will see that there is no Age field.





Run the following code to deserialize the object from the file.

static void DeserializeData()
{
    Customer c = null;

    XmlSerializer serializer = new XmlSerializer(typeof(Customer));
    FileStream fs = new FileStream("simple.xml", FileMode.Open);

    c = (Customer)serializer.Deserialize(fs);
    fs.Close();

    Console.WriteLine("Age : " + c.Age);
    Console.WriteLine("Specified : " + c.AgeSpecified);
}

Now run the serialize and deserialize code again, but this time set the AgeSpecified to true, and below is
the output :

Labels: DotNet