no decription about ShouldSerialize* pattern use in XmlSerializer

[trivalik]

Describe the issue or suggestion

The XmlSerializer allows that class to serialize specifiy a ShouldSerialize* method, to prevent serialization in certain cases, i.e. array is empty. This is somehow documented for winforms but not for XmlSerializer.

Important difference to Winforms implementation is that the method has to be public!

I am right now not sure if there are Reset and *Specified working.

Here a tested example:

using System.Xml.Serialization;

public class MyClass
{
    [XmlArray("Names")]
    [XmlArrayItem("Name")]
    public string[] Names { get; set; }

    // Control whether the array is serialized
    public bool ShouldSerializeNames()
    {
        return Names != null && Names.Length > 0;
    }
}

class Program
{
    static void Main()
    {
        var serializer = new XmlSerializer(typeof(MyClass));

        // Example 1: null array
        var objNull = new MyClass { Names = null };
        serializer.Serialize(Console.Out, objNull);
        Console.WriteLine();

        // Example 2: Empty array
        var objEmpty = new MyClass { Names = Array.Empty<string>() };
        serializer.Serialize(Console.Out, objEmpty);
        Console.WriteLine();

        // Example 3: filled array
        var objWithValues = new MyClass { Names = new[] { "Jeff" } };
        serializer.Serialize(Console.Out, objWithValues);
    }
}