c# - 无法将 Action <TDerivedThing>分配给 Action <IThing>

我有以下类定义：

public class Registry
{
     private List<Action<IThing>> _thingActions = new List<Action<IThing>>();

     public Register<TDerivedThing>(Action<TDerivedThing> thingAction)
          where TDerivedThing : IThing
     {
        // this line causes compilation issue
        _thingActions.Add(thingAction);
     }
}

为什么这会抱怨不能将Action<TDerivedThing>分配给Action<IThing>，我应该如何解决呢？

最佳答案

当然不是，即使EventArgs是对象，也不能将List<EventArgs>分配给List<object>。

 public void Register<TDerivedThing>(Action<TDerivedThing> thingAction)
      where TDerivedThing : IThing
 {
    _thingActions.Add(t => thingAction(t as TDerivedThing));
 }

可能是一个解决方案，但我不知道您的应用程序。