public static string[] FindEvents(Type senderType, Type argsType, Func <string, bool> exclude)
{
var found = MatchedEventNames.GetOrAdd(new Tuple <Type, Type>(senderType, argsType), tuple =>
{
var events = CandidateEvents.GetOrAdd(senderType, t =>
{
return(t.GetEvents(BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy)
//we can only look for events handlers with generic types because that is the only
// way that we can try to find a matching event based on the arg type passed in
.Where(x => x.EventHandlerType?.IsGenericType ?? false)
.Select(x => new EventInfoArgs(x, x.EventHandlerType !.GetGenericArguments()))
//we are only looking for event handlers that have more than one generic argument
.Where(x =>
{
if (x.GenericArgs.Length == 1)
{
return true;
}
//special case for our own TypedEventHandler
if (x.EventInfo.EventHandlerType?.GetGenericTypeDefinition() == typeof(TypedEventHandler <,>) && x.GenericArgs.Length == 2)
{
return true;
}
return false;
})
.ToArray());
});
/// <summary>
/// Finds the event name on the sender that matches the args type
/// </summary>
/// <param name="senderType"></param>
/// <param name="argsType"></param>
/// <param name="exclude">
/// A filter to exclude matched event names, this filter should return true to exclude the event name from being matched
/// </param>
/// <returns>
/// null if not found or an ambiguous match
/// </returns>
public static Attempt <EventNameExtractorResult> FindEvent(Type senderType, Type argsType, Func <string, bool> exclude)
{
var found = MatchedEventNames.GetOrAdd(new Tuple <Type, Type>(senderType, argsType), tuple =>
{
var events = CandidateEvents.GetOrAdd(senderType, t =>
{
return(t.GetEvents(BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic)
//we can only look for events handlers with generic types because that is the only
// way that we can try to find a matching event based on the arg type passed in
.Where(x => x.EventHandlerType.IsGenericType)
.Select(x => new EventInfoArgs(x, x.EventHandlerType.GetGenericArguments()))
//we are only looking for event handlers that have more than one generic argument
.Where(x =>
{
if (x.GenericArgs.Length == 1)
{
return true;
}
//special case for our own TypedEventHandler
if (x.EventInfo.EventHandlerType.GetGenericTypeDefinition() == typeof(TypedEventHandler <,>) && x.GenericArgs.Length == 2)
{
return true;
}
return false;
})
.ToArray());
});
return(events.Where(x =>
{
if (x.GenericArgs.Length == 1 && x.GenericArgs[0] == tuple.Item2)
{
return true;
}
//special case for our own TypedEventHandler
if (x.EventInfo.EventHandlerType.GetGenericTypeDefinition() == typeof(TypedEventHandler <,>) &&
x.GenericArgs.Length == 2 &&
x.GenericArgs[1] == tuple.Item2)
{
return true;
}
return false;
}).Select(x => x.EventInfo.Name).ToArray());
});
var filtered = found.Where(x => exclude(x) == false).ToArray();
if (filtered.Length == 0)
{
return(Attempt.Fail(new EventNameExtractorResult(EventNameExtractorError.NoneFound)));
}
if (filtered.Length == 1)
{
return(Attempt.Succeed(new EventNameExtractorResult(filtered[0])));
}
//there's more than one left so it's ambiguous!
return(Attempt.Fail(new EventNameExtractorResult(EventNameExtractorError.Ambiguous)));
}