c# - 使用 MulticastDelegate 作为参数同时避免 DynamicInvoke

Question

我有一个 MulticastDelegate，它可以引用具有相同签名的多个(遗留)委托(delegate)之一。例如:

public delegate void ObjectCreated(object sender, EventArgs args);
public delegate void ObjectDeleted(object sender, EventArgs args);
//...

然后使用这些委托(delegate)来定义事件:

public event ObjectCreated ObjectWasCreated;
public event ObjectDeleted ObjectWasDeleted;

然后我有一个方法接收一个 MulticastDelegate，我用它来做一些常见的检查:

void DispatchEvent(MulticastDelegate handler, object sender, EventArgs args)
{
    if (handler != null)
    {
        // ...
        handler.DynamicInvoke(sender, args);
    }
}

从定义事件的类的其他方法中调用:

DispatchEvent(ObjectWasCreated, sender, args);
DispatchEvent(ObjectWasDeleted, sender, args);

是否有更简洁的方法来避免 DynamicInvoke？

Answer 1

这是我的无反射解决方案。它基本上将多播委托(delegate)实现为列表。更少的代码？不，更好的表现？我不知道。清洁工？嗯。

public delegate void ObjectCreated(object sender, EventArgs args);
public delegate void ObjectDeleted(object sender, EventArgs args);

public event ObjectCreated ObjectWasCreated
{
    add
    {
        m_ObjectCreatedSubscribers.Add(value.Invoke);
    }
    remove
    {
        m_ObjectCreatedSubscribers.RemoveAll(e => e.Target.Equals(value));
    }
}
public event ObjectDeleted ObjectWasDeleted
{
    add
    {
        m_ObjectDeletedSubscribers.Add(value.Invoke);
    }
    remove
    {
        m_ObjectDeletedSubscribers.RemoveAll(e => e.Target.Equals(value));
    }
}

private List<Action<object, EventArgs>> m_ObjectCreatedSubscribers = new List<Action<object, EventArgs>>();
private List<Action<object, EventArgs>> m_ObjectDeletedSubscribers = new List<Action<object, EventArgs>>();

void DispatchEvent(List<Action<object, EventArgs>> subscribers, object sender, EventArgs args)
{
    foreach (var subscriber in subscribers)
        subscriber(sender, args);
}