事件实例字段成员可以为null（假设它没有强制设置为null）吗？

Question

Suppose I have this as a member of a class:

public event EventHandler<MyObject> SomeEventThing;

to avoid a nullable reference warning, I have to write:

public event EventHandler<MyObject>? SomeEventThing;

Does this mean the event field could be null and I've been playing with fire the entire time? Or is this an analyzer bug?

Answer 1

Yes, a field-like event can absolutely be null - and will be if there are no subscribers to the event. The compiler is correct. The generated event code is backed by a field of the delegate type, and the default value of the field is still null like other reference type fields.

Note that with the null-conditional ?. operator, it's easy to conditionally invoke the event handlers:

SomeEventThing?.Invoke(this, new EventArgs<MyObject>());