C#–Never place an event inside a struct; C# event is always null inside a struct

When you write something similar to:

namespace XXX
{   
    public struct SomeStruct
    {
        public event SomeDelegate SortDirectionChanged;
    }

    public delegate void SomeDelegate(SomeInfo input);
}   

then SortDirectionChanged event will always be null.
So when you try to set a delegate to the event like this:

var sth = new SomeStruct();
sth.SortDirectionChanged += SomeMethodServingEventCall;

SortDirectionChanged will be null when you'll try to pass on the struct. (when you check it with a debugger right after the assignment it will appear to be ok – strange). Use class instead.