Keep sort when deserialize and serialize XML using XmlSerializer

Question

I have the following test XML string:

 b1
 a2         


        

Answer 1

You can do this with XmlSerializer by using a single collection to capture both the and elements and applying the [XmlElement(Name, Type = typeof(...))] attribute to it multiple times, once for each desired element name. Because you are using a single collection to deserialize both elements, the order is automatically preserved. However, to make this work, XmlSerializer must be able to determine the correct element name when re-serializing. There are two approaches to accomplish this, as documented in Choice Element Binding Support:

1. If the collection contains polymorphic items, the element name can be mapped to the concrete item type by using the [XmlElementAttribute(String, Type)] constructor. For instance, if you have a sequence of elements that might be strings or integers like so:

   
      Hello
      999
   
   

   This can be bound to a collection as follows:

   public class Things
   {
       [XmlElement(Type = typeof(string)),
       XmlElement(Type = typeof(int))]
       public List