Question

I’m trying to basically make a system which allows me to load in multiple types of enemies. One type of enemy requires more elements than the others. So for example.

XDocument doc = XDocument.Load("Levels\\Level"+ levelIndex + "\\Waves" + levelIndex + ".xml");

List<WaveInfo> waveInfo = new List<WaveInfo>();


        waveInfo = (from wave in doc.Descendants("wave")
                          select new WaveInfo()
                          {
                          enemiesInfo = (from i in wave.Descendants("enemy")
                                     select new EnemyInfo()
                                     {
                                         type = Convert.ToInt32(i.Element("type").Value),
                                         colour = Convert.ToInt32(i.Element("colour").Value),
                                         speed = (float)Convert.ToDouble(i.Element("speed").Value),
                                         spawnTime = (float)Convert.ToDouble(i.Element("spawnTime").Value),
                                     }).ToList()
                          }).ToList();

This works fine and can load both types of enemy in. But in my xml I’m having to add a colour element to an enemy type that doesn’t require it. What I would like to happen is that with one type of enemy I can just not bother writing the colour tags and the serializer just processes that as a null value. How can I do this?

Answer 1

This should work:

colour = i.Element("colour") != null ?
        Convert.ToInt32(i.Element("colour").Value) : 0,

Or, better yet you can use an explicit operator, like this one, like so:

colour = (int?)i.Element("colour") ?? 0,