protected object ConvertToDelegate(object o, Type toType)
{
var toMethodInfo = toType.GetMethod("Invoke");
var toMethodParams = toMethodInfo.GetParameters();
var toMethodParamCount = toMethodParams.Length;
MethodInfo fromMethod;
object fromObject;
FindMethod(o, toMethodParamCount, out fromObject, out fromMethod);
// simplest case - when parameters are contravariant and result is covariant
var toDelegate = Delegate.CreateDelegate(toType, fromObject, fromMethod, false);
if (toDelegate != null)
{
return(toDelegate);
}
// use adapter with run-time types conversion
var adapter = new DelegateAdapter(fromObject, fromMethod);
foreach (var adapterMethod in adapter.GetType().GetMethods())
{
if (adapterMethod.Name == "Invoke" && adapterMethod.GetParameters().Length == toMethodParamCount)
{
var resType = toMethodInfo.ReturnType != typeof(void) ? toMethodInfo.ReturnType : typeof(object);
var genericTypes = new Type[toMethodParamCount + 1];
for (int i = 0; i < toMethodParams.Length; i++)
{
genericTypes[i] = toMethodParams[i].ParameterType;
}
genericTypes[toMethodParamCount] = resType; // last type for result
var typedInvokeMethod = adapterMethod.MakeGenericMethod(genericTypes);
LogManager.GetLogger(typeof(DelegateConverter)).Write(LogEvent.Info, typedInvokeMethod.ToString());
return(Delegate.CreateDelegate(toType, adapter, typedInvokeMethod, true));
}
}
throw new InvalidCastException();
}
