Serializing multiple List<T> objects in to the same XML file C#

Question

Hello everyone I have three lists containing objects from the same class. For example, here are my lists:

    List<Course> courselvl4 = new List<Course>();
    List<Course> courselvl5 = new List<Course>();
    List<Course> courselvl6 = new List<Course>();

I was wondering if it is possible, to serialize each of these lists in to the same XML file and deserialize back in to the lists. Thanks. I have tried looking for the answer, but can not find it anywhere. Please direct if answered already.

Answer 1

You can go for this if you want to initialize your list with the proper capacity:

Int32 capacity = courselvl4.Count + courselvl5.Count + courselvl6.Count;

List<Course> courses = new List<Course>(capacity);
courses.AddRange(courselvl4);
courses.AddRange(courselvl5);
courses.AddRange(courselvl6);

Alternatively:

List<Course> courses = courselvl4
                 .Concat(courselvl5)
                 .Concat(courselvl6)
                 .ToList();

Then just go for:

SerializeCourses("CoursesList",courses);

private static XDocument SerializeCourses(String rootElement, List<Course> courses)
{
    XDocument doc = new XDocument();

    using (XmlWriter writer = doc.CreateWriter())
    {
        writer.WriteStartElement(rootElement);

        foreach (Course course in courses)
            new XmlSerializer(typeof(Course)).Serialize(writer, course);

        writer.WriteEndElement();
    }

    return doc;
}