Cast to generic type in C#
c#, casting, generics
Solution
Does this work for you?
interface IMessage
{
void Process(object source);
}
class LoginMessage : IMessage
{
public void Process(object source)
{
}
}
abstract class MessageProcessor
{
public abstract void ProcessMessage(object source, object type);
}
class MessageProcessor<T> : MessageProcessor where T: IMessage
{
public override void ProcessMessage(object source, object o)
{
if (!(o is T)) {
throw new NotImplementedException();
}
ProcessMessage(source, (T)o);
}
public void ProcessMessage(object source, T type)
{
type.Process(source);
}
}
class Program
{
static void Main(string[] args)
{
Dictionary<Type, MessageProcessor> messageProcessors = new Dictionary<Type, MessageProcessor>();
messageProcessors.Add(typeof(string), new MessageProcessor<LoginMessage>());
LoginMessage message = new LoginMessage();
Type key = message.GetType();
MessageProcessor processor = messageProcessors[key];
object source = null;
processor.ProcessMessage(source, message);
}
}
This gives you the correct object. The only thing I am not sure about is whether it is enough in your case to have it as an abstract MessageProcessor.
Edit: I added an IMessage interface. The actual processing code should now become part of the different message classes that should all implement this interface.
Problem
I have a Dictionary to map a certain type to a certain generic object for that type. For example: ``` typeof(LoginMessage) maps to MessageProcessor<LoginMessage> ``` Now the problem is to retrieve this generic object at runtime from the Dictionary. Or to be more specific: To cast the retrieved object to the specific generic type. I need it to work something like this: ``` Type key = message.GetType(); MessageProcessor<key> processor = messageProcessors[key] as MessageProcessor<key>; ``` Hope there is a easy solution to this. Edit: I do not want to use Ifs and switches. Due to performance issues I cannot use reflection of some sort either.