Question

When using XML serialization to serialize a class, how to make some attribute be outputted conditionally. i.e. In some case, it output this attribute, in other cases, it does not.

Answer 1

You can create an additional property which is called MyPropertySpecified, which returns a boolean.
When this property returns true, the MyProperty property will be serialized. When it returns false, it will not be serialized.

Also, you’d want to decorate that property with the XmlIgnoreAttribute, so that this specific property is not serialized.

Example:

public class Person
{
    public string Name
    {
        get;
        set;
    }

    [XmlIgnore]
    public bool NameSpecified
    {
        get  { return Name != "secret"; }
    }
}