EntityComponentSystem usage - custom components

#1

I’ve started writing my own ECS, just to see how they work. But I’m also trying to work out how to use the Paradox ECS.

Now I have a MeleeComponent and HealthComponent so far, written in my own basic ECS which I’m trying to rework to use the EntityComponent instead. However I am getting a NotImplementedException, but strangely, I’m not being told what I haven’t implemented. I’m guessing that it’s the DefaultKey that needs to be overridden. But I don’t really know what to do here …

So my HealthComponent looks like this

    public class HealthComponent : EntityComponent
{
    public HealthComponent() : base() 
    {
        DefaultKey =  // ** What do i do here ? **
        
    }
    public int Max { get; set; }
    public int Current { get; set; }
}

Edit : So if I setup a private field for my custom component

private PropertyKey defaultKey;
defaultKey = new PropertyKey<Components>("HealthComponent",typeof(Components), null);

then override PropertyKey DefaultKey with

     public override PropertyKey DefaultKey { get { return defaultKey; } }

I get an invalid cast exception when i try to add the compoent to my entity. As you you can probably see, I don’t really know what I’m meant to be doing here.

#2

I took a look at the PhysicsComponent to see how it’s done there and sure enough I got my answer …

public static PropertyKey<HealthComponent> Key = new PropertyKey<HealthComponent>("Key", typeof(HealthComponent));
 public override PropertyKey DefaultKey { get { return Key; } }