Converting generic type to it's base and vice-versa
- by Pajci
Can someone help me with the conversion I am facing in enclosed code ... I commented the lines of code, where I am having problem. Is this even the right way to achieve this ... what I am trying to do, is forward responses of specified type to provided callback.
public class MessageBinder
{
private class Subscriber<T> : IEquatable<Subscriber<T>> where T : Response
{
...
}
private readonly Dictionary<Type, List<Subscriber<Response>>> bindings;
public MessageBinder()
{
this.bindings = new Dictionary<Type, List<Subscriber<Response>>>();
}
public void Bind<TResponse>(short shortAddress, Action<ZigbeeAsyncResponse<TResponse>> callback)
where TResponse : Response
{
List<Subscriber<TResponse>> subscribers = this.GetSubscribers<TResponse>();
if (subscribers != null)
{
subscribers.Add(new Subscriber<TResponse>(shortAddress, callback));
}
else
{
var subscriber = new Subscriber<TResponse>(shortAddress, callback);
// ERROR: cannot convert from 'List<Subscriber<TResponse>>' to 'List<Subscriber<Response>>' ... tried LINQ Cast operator - does not work either
this.bindings.Add(typeof(TResponse), new List<Subscriber<TResponse>> { subscriber });
}
}
public void Forward<TResponse>(TResponse response)
where TResponse : Response
{
var subscribers = this.GetSubscribers<TResponse>();
if (subscribers != null)
{
Subscriber<TResponse> subscriber;
Type responseType = typeof (TResponse);
if (responseType.IsSubclassOf(typeof (AFResponse)))
{
// ERROR: Cannot convert type 'TResponse' to 'AFResponse' ... tried cast to object first, works, but is this the right way?
var afResponse = (AFResponse)response;
subscriber = subscribers.SingleOrDefault(s => s.ShortAddress == afResponse.ShortAddress);
}
else
{
subscriber = subscribers.First();
}
if (subscriber != null)
{
subscriber.Forward(response);
}
}
}
private List<Subscriber<TResponse>> GetSubscribers<TResponse>() where TResponse : Response
{
List<Subscriber<Response>> subscribers;
this.bindings.TryGetValue(typeof(TResponse), out subscribers);
// ERROR: How can I cast List<Subscriber<Response>> to List<Subscriber<TResponse>>?
return subscribers;
}
}
Thank you for any help :)
